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31 featured content items: Featured articles (30) H, He, O, F, Zn, Ge, Y, Nb, Tc, Xe, Cs, Pb, At, Fr, Th, U, Pu, Cf, Db, Hs, Nh, Ts, Og, noble gas, metalloid, periodic table, heavy metals, radiocarbon dating, history of aluminium, island of stability Featured topics (1) period 1 elements Signpost interviews: 2011, 2013 view edit Detailed list Article quality in the periodic table Other high-quality articles

On the periodic table article more generally

I admit that I haven't read all of the above. I am aware of the La v Lu and related debates in the literature and here, and also on the style of colouring the PT on WP. I have also looked through our article on the periodic table, and I am wondering if the debates here are the most important, or whether they go to the issues from the perspective of encyclopaedic content. We are writing for the average of 30,000+ page viewers per day, most of whom will not be chemists with broad knowledge of the topic. Some examples:

Overview – the first section after the lede

I invite you all to stop for a moment and think about what a non-chemist needs to know in the overview of the PT at the start of our article. If you don't remember what is in our article, all the better. I suggest stopping to jot down a few points. If you were asked by someone about the PT, someone with little knowledge, what would you tell them?

Ok, here is the Overview we give. In sequence, it says:

1. Below is a widely-used layout but there are others discussed later
2. 18 column PT provided
3. Every element has a Z giving the number of proton, followed by a note about Z = 0 for neutronium – which isn't on this PT and having mentioned only protons
4. A section about differing neutrons and isotopes – which are not separated on the PT – and going on to atomic masses of of most stable of the non-stable isotopes in parentheses
5. Listed in order of increasing Z. Rows/periods when a new electron shell has its first electron, columns / groups by electron configuration.
6. "elements with the same number of electrons in a particular subshell fall into the same columns (e.g. oxygen and selenium are in the same column because they both have four electrons in the outermost p-subshell)"
7. "Elements with similar chemical properties generally fall into the same group in the periodic table, although in the f-block, and to some respect in the d-block, the elements in the same period tend to have similar properties, as well"
8. "Thus, it is relatively easy to predict the chemical properties of an element if one knows the properties of the elements around it"
9. 118 confirmed elements, most recent discoveries confirmed in December 2015 and names / symbols in November 2016 (Nh, Mc, Ts, Og)
10. first 94 elements occur naturally (83 are primordial and 11 occur only in decay chains of primordial elements); the remaining 24 synthesized in laboratories
11. No element heavier than einsteinium (element 99) has ever been observed in macroscopic quantities in its pure form, nor has astatine (element 85); francium (element 87) has been only photographed in the form of light emitted from microscopic quantities (300,000 atoms)

Is this really what a reader needs? Just some points that occur to me, and a suggested sequence:

• This is the periodic table of elements yet there is no explanation of what an element is or why they are tabularised. Maybe define atoms as the building blocks of normal matter and that the table has evolved throughout history and is still being modified based on additional research as a way to summarise the properties.
• Stating that all elements are made of atoms, each consisting of a nucleus with protons and (usually) neutrons, surrounded by an electron cloud to provide charge balance
• Then address that 94 occur naturally and others have been synthesised
• Diagram of single PT cell, noting it provides name, symbol, atomic mass, atomic number = Z. Atomic mass the weighted average of naturally occurring isotopes
• Chemical properties largely arise from electrons and their configuration. Neutral atom, electrons = Z but can gain or lose to become ions
• Then offer PT, perhaps coloured just for shells / sub-shells to indicate that organisation occurs by preceding from previous element and looking to where the additional electron is placed – covering s-, p-, d-, and f- blocks and electronic configurations
• The present statement (6) is not correct. If O and Se are in the same column because they have 4 electrons in p subshell, why aren't they in same column as Be (as all have 2 electrons in outermost s subshell). Further, Cr is in group 6 suggesting a d configuration but we all know it is actually sd, making positioning unclear under this statement. I know the answers, of course, but would a non-chemist understand from the statement made?
• Statement (7) – perhaps more useful to say that arrangement historically placed chemically similar elements together and that the arrangement by electronic configuration retains this as the similarity in valence shell configuration explains the similarity in chemical properties
• For heavier elements, and especially those in the f-block and to some extent the d-block, elements share similarities across periods. For this reason, the properties of elements can be predicted relatively easily in these parts of the PT if the properties of surrounding elements are known.
• This arrangement led to gaps for missing elements being identified and predictions made about their properties, which proved useful in the search for missing elements. All such gaps have now been filled. All elements up to einsteinium (element 99) have been observed in macroscopic quantities in pure form, with two exceptions - astatine (element 85) and francium (element 87), though the light emitted due to radioactive decay of a microscopic quantity of francium (300,000 atoms) has been photographed. No element beyond einsteinium has been observed in macroscopic form.
• Historically, alchemists sought elemental transmutation, changing one element into another – can only be achieved by changing the nucleus whereas chemical processes only rearrange electrons. However, by introducing radioactivity, we find that elements can spontaneously decay in which the nucleus is changed and element is transformed into another. The 94 naturally-occurring elements are divided into 83 primordial and 11 formed in the decay chains of some of the primordial elements
• Fusion, the combining of smaller atoms into larger ones, is possible and is responsible for the energy coming from the sun, and for the formation of all elements heavier than H. Fission, the splitting of heavier elements, can also be achieved for some elements and occurred for uranium and plutonium in Hiroshima and Nagasaki, respectively, at the end of WW2.
• Since WW2, scientists have investigated fusion processes to prepare new elements and in so doing have added 24 new elements to the PT, the latest being Nh, Mc, Ts, and Og that were confirmed in December 2015 and had their names / symbols assigned in November 2016. In each case, the new elements need evidence of their chemical properties to confirm that their anticipated position in the PT is correct. The mass shown is for the isotope of greatest stability, and given in parentheses to indicate that it is synthetic.
• Arrangements and categorisations have been debated over time. The historical division of elements into metals and non-metals based on chemical properties has been expanded to include metalloids with similarities to each group. Metals within the s-block are sometimes subdivided into alkali metals (group 1) and alkaline earth metals (group 2), while the d- and f-block elements are sometimes called transition metals and inner transition metals, respectively. The non-metals are also sub-categorised by groups into the pnictogens, chalcogens, halogens, and noble gases, though this leaves hydrogen and boron uncategorised. 18 column periodic tables have varying placements of the f-block, reflecting different views of the appropriate location for elements like lanthanum and lutetium. The PT below presents one widely-used layout, with colourings to signify categorisations within the PT as a means to concisely summarise the wealth of knowledge of the elements.

Going on from there, the PT article goes into categories, metals v non-metals, etc, which seems more like the content for an article on the history of the elements than for an article on the PT. After outlining what the PT is, doesn't next come history (how it came to be that way) with element properties history that led to changes in the PT appearing at the appropriate point in the development of the PT?

Do others see that we have a problem with the structure of the PT article itself, and that we should discuss this first? For example, I can see how the debate about colouring and blocks v. categories in the PT in the overview arises. For me, the table given is too complex, though it is suited for the lede image and the article, but in reorganising the overview in some way (perhaps as I suggest off the top of my head), there becomes a natural presentation with the categories complicated one at the end and a blocks option preceding it.

Thoughts \ Comments \ Suggestions \ Criticisms \ etc? EdChem (talk) 03:19, 17 October 2020 (UTC)

@EdChem: The periodic table is a map. In an encyclopaedia, world maps are usually coloured by region. Your thoughts are refreshing albeit they don't address the substance of many of our discussions re how to colour the map. That is to say, a reorganising of the article, in order to improve its clarity, can be done by anyone who gives some thought to its presentation flow, as you have carefully done.

The debates about colouring are not that important in one sense but on the other hand we like to get things "right", so to speak, and doubts have been raised among us, as to wether this is in fact the case.

From a survey of 62 more recent chemistry textbooks, just 15% confine their lede periodic tables to showing just the blocks. Hence the interest, as an encyclopaedia, in showing more than this. Encyclopedia Britannica starts with nine categories (their table and its colour scheme predates ours); the most popular periodic table in the web emulates the WP table. Sandbh (talk) 05:46, 17 October 2020 (UTC)

@Sandbh: Not quite, when it comes to https://ptable.com/ – you will notice that they colour the Zn group as transition metals even though we don't, that they talk about "lanthanoids" and "actinoids" following IUPAC even though we don't, that they show the table in 18-column form with a gap under yttrium even though we don't, and that when you click "Wide" or those placeholders the table expands to the Sc-Y-Lu form that we had in 2016 and that I still think we made a mistake in ever leaving. So even when the categories are this similar we can't expect agreement in other sources in quite the same way we can expect it (outside group 3) when it comes to the question "which element is in which block?". As for EB, they depart from ours even more strongly, by saying that group 3 are apparently not transition metals (although group 12 is – so much for IUPAC), accepting to use "halogens" as a category (with At and Ts coloured as halogens!), and refusing to use "metalloids" as a category. Categories are common indeed, but no one agrees on what they are and what elements go where. Why take a side, I ask? And are we even allowed to take a side by policy, I ask? ^_^ Double sharp (talk) 10:25, 17 October 2020 (UTC)

• @EdChem: Good and well-written point, EdChem. The short explanation (not justification) is: in my experience, the term "overview" was primarily used to give a visual overview of the graphic table itself full stop. As you write, that is not enough, especially since there is only this one section (no subsections) for what is the encyclopedic essence. I'll think of a new setup, using your numbered bulleted list. -DePiep (talk) 09:42, 17 October 2020 (UTC)

DS comment

@EdChem: I think you are almost totally right, both about what you suggest, and that the debates here are strictly speaking less important than how the lede and the overview are not doing their jobs. (In fact, there's at least one statement in the lede that is flat-out wrong. Six groups do not have accepted names, because IUPAC never said that the names applied to the whole group. Only for the alkaline earth metals did they name all the known elements in the group, and when element 120 is discovered that also goes out the window. ^_^)

In fact you remind me of my somewhat-naughty-for-WP user subpage when I tried to write as an example what I'd do if I had my pedagogical hat on rather than my encyclopaedic hat on: User:Double sharp/Teaching periodicity! That's certainly not OK for WP, but I now think it was worth doing as an exercise because even though the language changes a lot, it certainly sheds light on what the logical sequence is supposed to be.

I just have two little pet peeves with what you propose (albeit ones I can substantiate by reliable sources). Please don't take my expounding on this at length the wrong way; I love everything else about it. I just really really dislike especially the first one being gotten wrong when we actually have reliable sources getting it right. ^_^

Blocks, differentiating electrons, and electronic configurations.

This is something that I have had to complain about for ages, but no, the blocks do not come from the electron that differentiates an element from the previous one. I am sure of course that you know this, but I think we should not simplify this in such a way that the resulting statement is incorrect. Simplify yes, but we have to keep things correct; this is an encyclopaedia, we will get readers of every level, and we should probably not lie to children. To substantiate my case, I give some reliable sources below.

Yes, I know some books say that blocks come from differentiating electrons. But I think this is outweighed by the fact that reliable sources are in agreement that electrons are literally indistinguishable. (Not to mention that I have never seen any reliable source that succeeded in defining what a differentiating electron is in such a way that the definition actually applies to cases like vanadium ds proceeding to chromium ds, or lawrencium dsp proceeding to rutherfordium dsp, but that's a minor additional point.) Serious sources covering physics understand this. If you look at them, they may use the sloppy language, but they make it very clear and apologise that it is sloppy. Like Feynman's lectures on physics:

So we cannot single out the 2s electron in a lithium atom and call it the differentiating electron because we cannot even distinguish which electron is the 2s electron. Yes, he talks roughly about the "third electron", but he says it's a rough way of talking, and explains that in reality we cannot distinguish which is the third electron.

I realise that using the sloppy language is very tempting. I am often tempted to use it too. Some people who know better do it, like Eric Scerri who in 2009 made the point "electrons in any particular atom cannot be distinguished, which means that speaking of an atom as actually having this or that d electron for example is also strictly an approximation", but in 2019 still talked about differentiating electrons. But we're not a textbook and I don't think we should simplify things down to a level that is too likely to cause a misunderstanding. And, you know, we have a precedent for ignoring the textbooks when studies are clear that what they say isn't right. That would be hypervalence, where I'm sure you'll still find textbooks explaining SF₆ and friends with expanded octets and d orbitals because it's apparently still in some syllabi. The only problem is that we've known for a while that that's not true at all and that there is no significant d involvement there. So, as an encyclopaedia, we in fact reflect that understanding in our article on hypervalence even if textbooks are being sluggish. And that would be because school-level textbooks have something else constraining them other than the facts: they need to simplify things to the reader who is only just encountering something new, and even if they want to do things right, they may have to conform to the official syllabus in their country.

Similarly, reliable sources understand that the situation with d and f block configurations is actually not too significant, whence I quote Feynman again:

So it's not really that important that the configurations don't match. What we have, and every periodic table poster shows, are gas-phase configurations. This is a situation that is about as far from chemistry as you can get: a single atom with nothing else around. As Feynman quite clearly states, for many d elements the configuration can change depending on exactly what elements are around. This is also stated for f elements in Christian Jørgensen's lecture-paper The Loose Connection between Electron Configuration and the Chemical Behavior of the Heavy Elements (Transuranics). In the same author's review Influence of Rare Earths on Chemical Understanding and Classification he writes:

So, finding reliable sources to refute the simplification is not a trouble. The only trouble is that this is mostly explained in textbooks near the beginning of a chemistry course when d and f elements are not on anyone's mind, and so I suspect many textbooks will be sloppy about it just because the oversimplified version works perfectly for main group elements and the rest of the table can be swept under the rug. I know there is someone who explains it properly, and that's William B. Jensen:

Now, it's true that Jensen very strongly supports the Lu option, and that his criteria were stated in the context of that support. On the other hand, Lavelle in his reply (on the next page of that article) is a strong La supporter, and he also wrote "I agree with Jensen’s four points on classifying elements in the periodic table". Not to mention that the La vs Lu dispute is basically related to the foundations of what the PT is all about: outside textbooks, I suspect this is one of the few places where those things will be talked about rather than disregarded as obvious stuff known since school. Therefore I think we can use this one. It accords with the generally accepted science rather than being a pedagogical simplification; since we do not have our pedagogy hat on here, I feel we should focus on the former

So I'd replace some of your points in the middle (italics for what I've changed) with:

• Chemical properties largely arise from electrons and their configuration. Neutral atom, electrons = Z but can gain or lose to become ions
• Then offer PT, perhaps coloured just for shells / sub-shells to indicate that organisation occurs by looking at how many electrons are available for chemical reactions and which subshells they appear in; covering s-, p-, d-, and f- blocks.
• Statement (7) – perhaps more useful to say that arrangement historically placed elements with some chemical similarities together and that the arrangement by valence electrons and subshells retains this as the similarity in valence shell configuration explains the similarity in chemical properties.

This way, we avoid having to mention the electron configuration outright in the lede and need to explain exactly what needs to be fixed about that picture for the d and f elements; we cut straight to an easily explained version of the correct statement. A sentence on the problems with gas-phase configurations for d and f elements might be fine here only as a footnote. In the main body, of course, we can talk about this in a little bit more detail and promote it to the actual text.

And I say "elements with some chemical similarities" rather than "chemically similar elements" to avoid having wiseacres at the back of the classroom wonder how nitrogen and bismuth got into the same group even for Mendeleev. (I know, it's not a classroom, but probably the same personality type. ^_^) He was looking at the valence there, if I am not mistaken: for both elements maximum valence is +5. So that's a chemical property that matches even though many others don't, which is why I think my wording may be a bit better there. Again, it's just a fine line for me about being both simple and right.

Colourings to signify categories.

This thing at the very end segues into what I think is one of the two issues we are discussing. I don't even think we should colour to signify categories in the first place because nobody can agree on what categories to use and what their boundaries are. Yes, most textbooks show categories. But what categories? Anything we colour, like Se as a nonmetal rather than a metalloid (which one quarter of sources do!) or as a metal, picks a side. In the absence of a warning for just about any element near this borderline I feel that any colouring along a metallicity line gives undue weight to one side. Worse still, we outright put in places like {{infobox oxygen}} things like "Element category: Reactive nonmetal", as if the categories we had decided to use were the only ones that actually existed! No mention of chalcogens at all even though that is IUPAC-approved and "reactive nonmetals" is not! Meanwhile we cannot even get all the IUPAC-approved and common categories in there without overlaps (where did pnictogens and chalcogens go?)!

I think you are correct, EdChem, to prioritise pnictogens and chalcogens in the lede over those metallicity p block categories, because the former are actually IUPAC-approved and the latter are not. But I think that for the above reasons, what is best is to display nothing but blocks as a general thing for colouring our general PT images. Outside the group 3 issue (which is something else in itself), which elements belong in which block is at least something that is 100% agreed on by everybody. Many textbooks colour more than that indeed; but I find it likely that most of those textbooks also know what a block is and talk about it when explaining the structure of the periodic table.

Once that one almost-universally agreed thing is done, then we can talk about categories. And by talking about them, we eliminate the sticking point that many of them overlap and that chemists don't agree on the scope of each category. Sandbh has already given two sources that disagree with the WP colour scheme. The fact that the literature is split 50-50 on whether the Zn group should be considered transition elements or not should already caution us about any colour scheme in the first place! Those are hard to reflect in a picture where we have to colour each category clearly. But if we just want to describe where each category lives in the table with text, then everything is 100% fine!

So we can talk about the chalcogens category (O, S, Se, Te, Po), without in any way jeopardising other categories like metalloids that commonly includes Te and sometimes Po, or post-transition metals or the myriad of other similar categories that quite often include Po. And we can talk about the transition metals as a category while making it clear that there's disagreement in the literature about group 12, without having to pick a side when colouring. I feel that would reflect the large spread of what the sources do far better than any colouring choice would do. So I would prefer to replace your last sentence with: "The PT below presents one widely-used layout, with colourings to signify blocks; many tables also colour in specific categories, many of which are described below."

Looking forward to your comments. And sorry for spending so long on what amount to such minor proposed changes from what you've very kindly suggested when I love almost everything about what you've written; it's just that once you know that the first thing is not quite right, you get slightly annoyed whenever you see it wrong. ^_^ Double sharp (talk) 10:16, 17 October 2020 (UTC)

I am happy to find DS here saying what I wrote below (in an ec): for the first description of the PT, we could remove the categorisation and catogory colors. And to point to another suggestion DS made (in their userpage); from memory: "when discussing elements, we should talk about their concept as specimen , and forget about their appearance in RL chemistry" (IIRC). In element pages, that would mean we should move to bottom of page: diatomic substances (O₂), allotropes, std atomic mass even. Could also conceptually simplify the PT article. -DePiep (talk) 11:25, 17 October 2020 (UTC)

@DePiep: I don't remember exactly what I said, but from what you say it might have been the distinction between the chemical element as in atoms and as in simple substances. So, oxygen as in "the type of atom with eight protons in its nucleus", rather than as dioxygen the gas or ozone the gas, because oxygen the element is just as present in MgO or CO₂ as it is in O₂ or O₃. Sure, that's an important concept too: Jensen talks about it here. The only trouble is that this distinction is, AFAIK, not clear enough often in English-language sources. So while I would dearly like to get rid of the conflation of the two notions, as French Misplaced Pages could do, I am not sure if we can. Maybe we have to do what Polish Misplaced Pages does and admit that in our language "chemical element" has two meanings. Remember, on my userpages I sometimes say things that are not standard yet, just significant minority viewpoints that I happen to agree with, and I try to keep that separate from the articles. ^_^ Double sharp (talk) 12:52, 17 October 2020 (UTC)

P.S. Glad to hear you're in agreement too about categorisation and category colours. ^_^ But I go a bit further and advocate removing them altogether from the infoboxes and PT templates. There are simply too many categories in the literature that overlap and have fuzzy boundaries for me to think that trying to interpret this as "there are a finite set of categories we use, some elements are disputed" is acceptable. To my taste anyway. It is a failing at following reliable sources, IMHO, that we mark out oxygen as just a reactive nonmetal but not also as a chalcogen. The latter category is IUPAC-approved when the former is not; it just fits badly in a scheme that tries to cover every element once and once only. I once again plead that we follow reliable sources, and noting that categories may differ very widely whereas blocks don't outside the group 3 dispute, suggest that the best way to do that is to not take sides on categories by not colouring them everywhere. Only describing them. I strongly support saying in the articles things like "Selenium is a chalcogen, and has been variously classified as a nonmetal, metal, or metalloid (most often the former)" (for the selenium article); I do not support trying to reduce this situation to colouring it only as one category everywhere. Double sharp (talk) 13:06, 17 October 2020 (UTC)

Remove cat+colors altogether (except for dedicated articles + their PT graphs) better be discussed separately, to keep thread on topic. But indeed removing them when describing the PT in its main article is helpful (because: another non-essential detail; and a very attentionseeking distraction at that). Now let's look further on what more should be in/out of the Overview. -DePiep (talk) 13:26, 17 October 2020 (UTC)

@DePiep: OK, new top-level section coming at some point to keep that issue separate. I won't discuss it here anymore. ^_^ Double sharp (talk) 13:33, 17 October 2020 (UTC)

DePiep comment

Following up EdChems post.

• New Overview setup thoughts

As a first suggestion, we could overhaul the "Overview" section & intention like this.

In general: it should describe the PT's essence (structure, relations, resulting appearance). This also implies:

0. Leave out details that are irrelevant to the goal (advantage: makes it easier to build the descrition without sidetracking). So for the overview, do not mention: history (Mendeleev, intermediate PT forms), isotopes, discovery of elements (new, predicted, added noble gasses), open issues (He placement, group 3), difference between concept (specimen) of an element and its RL appearance: use the concept only (no allotropes, difference natural/synthetic, atomic mass vs. Z -- though A=Z+N might be needed), alternative structures (Janet's left step), alternative graphic layouts (18/32 column), categories and other secondary trends/patterns(!). However, is an extra, late subthread we can introduce a few of those, as being related to the PT.

Section: Overview (==-level). Subsections:

1. Section: Element. Note chemical and physical difference (we need later on). Mention valence (0, I-VIII). Add single cell graphic example+explanation.

2. Section: Build the PT yourself (as is has been build before). Step 1: Order all elements 1-118 in a single line, one cell each, by increasing Z. (This order shall not change!). Step 2: Add a linebreak and blank cells such that: in the second row, elements with similar chemical behaviour (same valence, by RxOy valence) are in the same column. Repeat this (you'll need six linebreaks, creating seven rows). +example maybe.

3. Section: PT graph (simplified into essentials only, add group valence, rm catcolors?)

4. Section: explain hiccups as simple as possible: A/B valence columns, no-valence for f-block, blank cells in upper part & blocks. Or write: "described and explained in ".

5. Section: Physical background. Shell filling & valence, blocks, A=Z+N (but not isotopes).

6. Section: Other patterns and properties (could be new ==-level section, still overview only), e.g.: categories (metal-nonmetal, maybe subcategories?), isotopes, RL appearance as A_{r, std} and allotropes, m.p. b.p., discovery of elements.

7. Section: Related topics. Introducing like isotopes, graphical variants, structural variants, some historical problems now solved.

Below, existing sections on PT aspects can stay (though checked for consistency, and reordered by being essential and non-essential aspects).

This tries to make a buildup line for a complete description. The tough parts will be to leave out details as much as possible, then write the remaining stuff to the point. From here on, I'll leave it to you to write it :-) -DePiep (talk) 11:02, 17 October 2020 (UTC)

@DePiep: I think you have a point: the overview should, to my taste, simply be about the theoretical justification for the PT where the PT comes from, how to read it, and the patterns that come from it. At the very least, I think the current organisation is simply not good: blocks and periods should come before categories, and Klechkovsky's / Madelung's rule should appear far earlier than it actually does. I am not so sure about some of the details you mention, but I think we are in agreement on the basic idea. I can try to write it, but I'm busy and it may take a while. ;) Double sharp (talk) 12:57, 17 October 2020 (UTC)

@Double sharp: Well, describe by theoretical justification is quite different from describe by the (historical, Mendeleevian) buildup. Looks like it is the approach from the opposite direction (explaining vs. discovering). If by theoretical justification you mean "Classification of an element in the periodic table is based on four steps" (per Jensen; you wrote above), with me the question raises: what 'classification' is that? Does it inevitable lead to the column/row structure, so essential to the PT? As opposed to, say, enwiki-like categories, or electron filling issues solved -- IMO not essential in this. A warning is that ascending Z has to be "verified" in step 4. As far as I, interested layman, understand it now, the theor'al.justif'ion, it would add a strong physical base (e.g., shell filling), but I do not recognise yet how it would describe periodicity encyclopedically. Alas, we'll see what others think. -DePiep (talk) 13:19, 17 October 2020 (UTC)

@DePiep: Yes, it's about the column/row structure. Jensen uses this to put elements in blocks, then in groups within blocks, and then verifies that the resulting placement may make sense. His approach is not everybody's, but the general idea that there's something about electronic structure that explains the PT structure is present across sources. The point of the periodic law is that the configurations of the atoms and hence the properties of the elements depend periodically on atomic number. So I'd describe periodicity as such (statements of the periodic law can be found in the literature) and then describe the subshell filling that justifies it. And I think this is already done in EdChem's proposal. Of course, historically that is not at all where it came from, but I think that is something that should be covered under "History".

As for the words "theoretical justification": yeah, in the literature this is apparently controversial, regarding the actual status of Klechkovsky's rule for one. I dislike that situation, but it is what it is and we have to reflect it. So, OK, I should have said basically where the PT comes from. So I've struck my words out and corrected it. ^_^ But let's work on the details later and focus on EdChem's proposal first. Double sharp (talk) 14:34, 17 October 2020 (UTC)

P.S. I guess perhaps it might be better now that I briefly think about it again to first show the table, mention that periods are rows and groups are columns and the blocks are those rectangular areas, before stating where all of this comes from to explain what they mean. Double sharp (talk) 15:38, 17 October 2020 (UTC)

YBG comments

@EdChem: Thank you for giving a fresh review to our PT article; I agree largely with what you say, but I have a few questions.

Where to from here? Here are some ideas, in no particular order.

1. Re #EdChem's PT article proposal @DePiep, Double sharp, and Sandbh: You have each expressed some agreement and some disagreements with EdChem's suggestions. Is there any subset of the suggestions that is generally agreed upon that could be implemented apart from the remainder? If so, I think a good first step would be to implement agreed upon aspects before deciding the areas where we have disagreement. But I don't know if those areas are in fact separable. Does anyone think this possible?
2. Re DePiep's #Build the PT yourself idea. This sounds like an excellent idea for an animated graphic. I'm not sure if this is something for WP or an off-wiki project.
3. Re Double sharp's #Colourings to signify categories, specifically Anything we colour ... picks a side. I have been struggling with how to do a better job of representing all names for sets of chemical elements and not just the "winners" from our past and future mega threads. I have come up with two ideas which I think can be and benefit our encyclopedia and could be implemented independently of any other efforts, and even more importantly, could remain in place even if we make substantial changes to our category coloring system. Here are my ideas:
   • (3a) For each named set of chemical elements, develop a page modeled after lists of metalloids. This represents a substantial amount of work, but I think it would have great benefit. If Sandbh were willing to take this on, we could depend on his research skills to make these lists complete and reflective of the literature.
   • (3b) Change our {{infobox element}} by replacing "Element category" with "Element categories" and including a list of all names for sets of chemical elements that generally include the given element, possibly distinguishing the sets an element is almost always included in from the sets that less frequently include it, but probably excluding sets that very rarely include the element. This also represents a substantial amount of work, and should eventually be coordinated with the previous work, but the first draft need not wait on that result. If DePiep were willing to take this on, we could depend on his template-building skill to fully integrate this information into our template system, maybe by adding {{Infobox element/symbol-to-category-list}}, something along the lines of {{Infobox element/symbol-to-valence-group}}

The common thread in these items is my desire to get the most reader-bang-for-the-editor-buck by finding changes that improve our corner of WP without waiting for some hard-to-reach consensus. By all means, we should tackle the more difficult issues, but at the same time we should intentionally find non-controversial efforts that provide us with significant improvement. This will maximize the benefit the readers receive from the effort we editors put in. YBG (talk) 18:13, 17 October 2020 (UTC)

@YBG: my replies in ~short:

re 1. Looks like both EdChem, DS and me agree that the Periodic table#Overview section needs a complete redesign. Note that this section is the only one in article that handles the whole if it; other sections are just aspects. (Just showing a PT graph with some clarifications is not enough). This is the general agreement. Listing details, subtopics and incidental miswritings as issues does not help, once appreciated that we do need a redesign to rewrite this encyclopedically. For this, I'd definitely prefer to agree on a general line of approach (say section titles) to describe the PT.

re 2. When I wrote "Build a PT yourself", that's not a final text proposal TBH. But it does say the good part: being good science, the Reader can reproduce the original, Mendelevian 'experiment'. (Personally, when introducing the PT to people I learned that, after defining 'element' first, the Z-order is not to be skipped (having to smuggle with weight vs. Z). Only then the rhythm eh periodicity can be introduced (my 'line break' thing is useful in such a talk). So I build my proposal along this 'Mendeleevian' line.

OTOH, Double sharp gives an other approach: describe periodicity from the physical atom model. Our first task is to find a good overall line for the Overview. To keep in mind: needs an encyclopedic result for sure.

re 3a. We could treat each "category" (i.e., any set of elements, not just our enwiki nine) equally, at least create a good set of articles & overvierw lists. However, could be that categories are not part of the future redesigned PT#Overview section at all ;-) -DePiep (talk) 18:48, 17 October 2020 (UTC)

re 3b. Of course we can develop that categories-list-per-element. Let's get the articles right first ;-) -DePiep (talk) 18:48, 17 October 2020 (UTC)

@YBG: about 'list of categories/sets an element is member of': here at #Element_membership_list I started that list for us to fill (to end up in new {{Infobox element/symbol-to-sets}} for automation). While in this thread here, better categories & coloring not be mentioned again without good reason (these are deemed futile to the new periodic table article's main overview). -DePiep (talk) 22:26, 17 October 2020 (UTC)

I'm happy with pretty much everything in EdChem's list that I didn't comment on. ^_^ In other words, other than some peeving in the middle about the exact significance of electronic configurations and how there is no such thing as a differentiating electron as agreed by such an august reliable source as Feynman, I pretty much like everything he wrote as it stands. (The second disagreement is just that I don't think we should colour categories at all.) So if it went through with just that one minor thing amended it would be fine. It just looks like a bigger disagreement than it really is because I quoted a bunch of reliable sources to back up what I'm saying.

I am pretty sure that Lists of metalloids#Appearance frequency clusters falls under WP:NOR. Specifically because it's statistical analysis per Misplaced Pages:What_SYNTH_is_not#SYNTH is not numerical summarization. Of course I would prefer User:EdChem to opine on that since he likely has a firmer grasp on policy than I do.

Personally, I don't understand why we have to give categories this much of a pride of place. As used in the literature, their names are mostly fuzzy, their existence can be fuzzy, their boundaries can be fuzzy. Everything is fuzzy! That's not a situation I think the infobox is worth using. And many of the category names that have been mentioned here are not even ones that would be widely recognisable. I still strongly suspect that "reactive nonmetal" is going to give chemists the question "reactive relative to what?" That's not so much a category in usage as it is a two-word phrase. And exactly which category name are we picking among the multitudes of names given for categories that are sort of like but possibly not quite the same as post-transition metals? Do we have to list all sixteen from Post-transition_metal#Related_groupings when listing the categories tin is in, or what?

Common names, that are in textbooks, that are approved by IUPAC, yes, those can be spared. We can still write in the articles things like "Sodium is an alkali metal", "Cobalt is a transition metal", "Holmium is a lanthanoid and one of the so-called rare earth metals". Those are all fine. And in the more problematic p block we can write things like "Arsenic is a pnictogen that has both metallic and nonmetallic properties; it has variously been classified as either a metal, a nonmetal, or a metalloid." Or maybe "Tennessine is a member of group 17 of the periodic table, but it is expected to behave quite differently from the halogens fluorine through astatine and should have predominating metallic properties". (Note how I avoid saying there if Ts is a halogen or not.) That is all fine with me. But let's not put them in the infobox as if such category assignments are fundamental to the element. They really are not. And they really are not agreed. Basically: I feel this is a way better job for article text than an infobox.

Yes, if you asked me to put on my pedagogy hat, then yes, I can very easily define for you clearly what a metal is. And I can very easily define for you some categories. And that can solve all those problems. But the literature isn't unified behind that, and it isn't even split up between a few options, and that isn't even a particularly common option. So, we can do that as we please in our own books, in our own articles, but not here on Misplaced Pages.

Now, the rest of it. Regarding "building up the PT": I am not sure how an animation would help. Because the way to build up the PT in reality depends on getting each element by itself, looking at its electron cloud structure. I am not sure how an animation really helps with that. Generally how it's done is to show the first few elements and then periodicity appears because Na-Ar match properties of Li-Ne (the first clear example), but for that it's easier to do if you see everything at once.

If we mostly agree that the section needs a redesign, I can dust off some of my mental drafts and produce something. Basically like a scientific description of how this whole thing was set up, i.e. not how it historically was discovered. But, now I need time again for RL. Later. ^_^ Double sharp (talk) 19:47, 17 October 2020 (UTC)

Drafting

Since the Inspiration Fairy has struck, here is a first draft of the lede section. Overview to come at her next visit. It is a rushed first draft, it is too long, and it does not read perfectly yet, but I think it does a better job at getting across the important stuff than what we have so far. ^_^ Double sharp (talk) 20:47, 17 October 2020 (UTC)

Yess. I like the energy. -DePiep (talk) 22:14, 17 October 2020 (UTC)

DS, I understood EdChem was criticising the #Overview section for being eh nopt encyclopedic. Now your link shows a new lede and a new colorisation (by block). I wonder: a. the lede folows from the article body. Why start there? and b. you #Overview section is quite rudimentary. Why not start there, and later on derive the lede+top image from it? -DePiep (talk) 22:30, 17 October 2020 (UTC)

Because the lede is supposed to be shorter and doesn't need me to fill out citation templates, that's the lame reason. I plan to write an Overview similar to what EdChem states (although I may move some things around), but it would have taken more time, and I think it is better that I could make something come out now rather than have something perfect come out too late. ^_^

Not to mention that I still need to formally write up as a proposal why I feel we made a mistake in ever abandoning the Lu form as a default. With the sources. But that's for another section. Double sharp (talk) 22:43, 17 October 2020 (UTC)

DePiep, I did imagine working on the overview while looking at what else can be better structured / organised and coming back to the lede at the end, but a different sequence doesn't matter so long as Double sharp recognises that the lede will likely be re-visited once the body is sorted. Also, Double sharp, I know that citations are not required by policy for the lede but I generally prefer to have them in the lede as it is a good way to make sure the lede is tied to the article (is every citation in the lede also in the article) and is tied to RS. It is easy to write a lede about a topic that one knows well but that can also be influenced by your own views (OR risk) or priorities (not reflecting the coverage in the article). Say a lede has citations 1 to 15, I can see that they all appear in the article, that they are used in its major sections (so coverage of all big ideas / concepts), and that looked at together, they cover or at least sample from the major sources (review articles, books, etc). Of course, no one has to take that approach, but it is what I have found to be effective for me.  :) EdChem (talk) 00:52, 18 October 2020 (UTC)

P.S. A minor request about that lede PT: could you help me (1) remove the stray line below period 1, (2) if possible add atomic numbers, and (3) if possible deliberately misalign the f block rows so that there is no vertical alignment with the d block columns? I do not want to give the readers the impression that La belongs in group 3, Ce belongs in group 4, etc. They have similarities (secondary relationships) but I feel it just confuses the particular readers that are not super advanced yet (and anyway in the 32 column form this all disappears). Double sharp (talk) 22:52, 17 October 2020 (UTC)

Did the graph things here. Fine tuning and Z's later on, now about the concepts you want to convey. -DePiep (talk) 00:06, 18 October 2020 (UTC)

@DePiep: Thanks. I'd rather it misalign entirely by a fraction of a column, if you can do that, to make it clear that not only is there no Sc-Y-Lu-Lr-La, there is also no Sc-Y-Lu-Lr-Ce or anything else. ;) Double sharp (talk) 00:19, 18 October 2020 (UTC)

Yes I know, but that is irrelevant now. Until it goes live, this is clear enough. I'd rather spend time on getting understanding your concepts. (to me, at this moment, it concernongly looks like you diverge from what EdChem intends to say). -DePiep (talk) 00:28, 18 October 2020 (UTC)

@Double sharp: I have a few comments. May I edit your draft page per my likings and then undo my edits, so that nothing changes but you could see what I think could be improved in the article history? I'll leave my rationales in the edit summaries.

As a more general comment, I think it would be great to highlight how the PT is actually used. Periodic tables often include non-essential details such as standard atomic mass. It would also be important to include a brief mention of how the PT went from being a bold idea people were cautious of to becoming as popular as it is today. That is something that I have yet to learn myself (although this information will sooner or later appear in history of the periodic table, likely thanks to ComplexRational), but that is a very important detail. On the other hand, I think blocks are given too much attention, and I would leave the group 3 and He controversies out of the lead section altogether; one way or another, they're both pretty minor, and I feel that any discussion about them should follow after a proper introduction of these elements, i.e. the big table in the Overview section.--R8R (talk) 10:01, 18 October 2020 (UTC)

@R8R: Please, please, go ahead! I started this just as a first draft so that we could get something started. If you want to change it, please do! Double sharp (talk) 10:59, 18 October 2020 (UTC)

@Double sharp: I've made a few changes. As promised, I undid them, but you can find them in the article history. Hopefully they will aid your future writing :)--R8R (talk) 11:59, 18 October 2020 (UTC)

@R8R: And I undid it back because I liked your changes a lot. ^_^ It will definitely be inspirational for writing the Background and Overview according to User:EdChem's proposal, thank you! Double sharp (talk) 12:02, 18 October 2020 (UTC)

Wow... that stimulated some discussion!

Thanks to everyone who has commented, and for having done so in a constructive and collegial manner. I was hoping to find support for the idea that the overview needs a re-write, but I guess after ANI was not expecting the idea to be enthusiastically embraced. I am grateful and encouraged, so thank you.

That having been said, I think some of the above is going in directions that I didn't expect. In no particular order:

• I think the lede needs work, but it is a summary of a topic / article. If I write an article from scratch, I'll sketch a brief lede and come back to it once the article is fairly stable / complete. It is difficult to summarise an article that is not written. Worse (IMO), doing a lede first makes it much easier to write what I think or add OR rather than reflect the RS / DUE etc that is built into the article itself. Double sharp, I am not saying that there is anything wrong with your draft (to be honest, I only glanced at it), but please think of it as a draft that likely would need revisiting after other changes.
• I started with the overview for several reasons:
  • It is the first proper section and doesn't tell a reader what they need, IMO (and we appear to all agree on that point)
  • It was meant as an example of reflection on what is there that can be applied to other sections, and I think some need serious work. I was hoping others might take a look at the rest and suggest other parts that don't meet readers needs.
  • I would like a discussion of what is good and what needs change from a global perspective rather than diving into detail immediately, though those observations are valued too.
• So, I was thinking of changing the overview section first, rather than the lede.
• If I may sample from a few ideas above:
  • The idea of new separate articles is one I had a while back too. Certainly there is the material for an article on categorisation or clustering of elements (to avoid the double-meaning of "grouping"), so long as there are sufficient RS to write it. There are oodles of sources and perspectives but also a huge risk of OR. Many sources (like textbooks) adopt some categorisation system without explaining or justifying it, and talking about that without RS that do would be OR. Thus, this is an interesting idea and a good one for resolving disagreements but we'd need to consider carefully whether it is a good idea in a policy sense.
  • Related, are there other new articles that could be appropriate? I know WP once had an article on La v Lu, is that worth reconsidering – or even broadening based on other PT geography issues.
  • Double sharp, I note your comments about electron configurations and electrons being indistinguishable. I don't view it as seriously as you appear to because I don't mean (and this is an exaggeration) that we take a He atom, with its two nice blue electrons in the 1s shell, and make Li by adding a proton and two neutrons to the nucleus, and a nice red electron which will sit in the 2s subshell and be distinguishable from the two blue electrons that were already there... because that would be both scientific drivel and highly misleading. I do agree that indistinguishability is important – just yesterday I was talking with a student about coordinate covalency and used the example of formation of NH₄ in a Lowry-Bronsted acid-base reaction and pointing out that the reaction involves a proton transfer and thus the formation of a coordinate covalent bond, but then emphasised that this model of how the bond forms does not mean that the resulting bond is in any way different from the preexisting nitrgogen–hydrogen bonds. On electron configurations, what I meant was that the difference in configuration from : 1s to :1s2s is that the change is the 3 electron configuration of Li has a 2s electron that the 2 electron configuration of He did not. Of course, that raises problems with cases like V to Cr, but we are also talking about an overview. I agree it should not be scientifically inaccurate but it does not have to canvass every issue. How it is presented ultimately is a matter for consensus decision, of course.
  • Sandbh, you are correct that I took no position on the colouring, and deliberately so. Firstly, it is contentious here so it needs to be discussed but other changes can be made while that continues. Secondly, I offered to help with policy and to hopefully foster collaboration and building to consensus, so starting with "I think X" would be either to take one side or to say both sides are wrong – hardly a good way to start given my goal to help resolve the dispute rather than inflaming it. Thirdly, I don't actually have a strong view on it beyond that the lens to examine it from is (IMO) how it assists / supports readers.
  • DePiep, your explanation of how the overview came to be sounds quite likely to me, and I agree that how it got there is much less important than the question of how useful it is. I wonder if the section should not begin as "Background" because what is an atom / element, etc, is necessary background to organising them into a table.
  • Double sharp, on Feynmann, one simple explanation of how to distribute 3 electrons and needing a new orbital is the Pauli exclusion principle – no two electrons in an atom may have the same set of quantum numbers. Since any orbital automatically has three the same, and there are only two values for spin, the maximum occupancy of an orbital is two. Once any two of the three electrons are assigned to 1s, the unassigned must be placed in shell 2 and energetics then dictates it will be in the 2s orbital. Of course, orbitals / subshells / shells and quantum numbers are required for this. How the configurations are arrived at is not relevant for an overview, nor are irregularities like Cr, nor are the issues of gas-phase single atoms rather than physical substances in macroscopic quantities. Like in so many other parts of chemistry, we are dealing with models to aid our understanding rather than with reality – (aside) how many times have I tried to get students to accept that for oxidation states, and dissuade them from permanganate having an Mn ion rather than a Mn centre covalently bound to four oxo moieties?
  • On my (7), if the term "valence electron(s)" is to appear, it too will need defining / explaining.
  • YBG, I like the approach of looking for areas of agreement to work on.
• I am concerned about OR. Some of the posting on this page, IMO, have drifted into OR and/or looking at single sources that do not meet the requirements of DUE. Textbooks are certainly reliable sources and if virtually all of them say X, which we know from the literature is actually an inaccurate simplification, we need to be very careful if we try to say Y cited to literature (particularly to little-cited literature). DUE calls for sources to be weighted by their prominence and widely-used textbooks are awfully prominent. They are also flawed at times, which leaves us with a dilemma. Some such issues might best be discussed at a noticeboard where community input is sourced. If undergraduate texts say X but a more nuanced statement Y is given by advanced books (Cotton and Wilkinson, for example) then we have an easier situation. It's also easier if IUPAC have made a definitive statement. Unfortunately, some of these issues are cases where WP (as an encyclopaedia) needs to be behind and wait for the sources to support a change to be present.

Finally, which of my thoughts / suggestions ends up being used is always subject to consensus. I know that's obvious by policy but I want to be totally clear that I don't believe my thoughts should have any more weight than anyone else's, nor do I expect that they will. I do think deciding what in the article should be kept, what should be changed, and what is contentious is worth identifying fairly soon, in part as it avoids work being reverted, etc. Thanks. EdChem (talk) 00:43, 18 October 2020 (UTC)

@EdChem: Yes, I understand. It's just that the whole differentiating-electron thing has become a particularly frustrating pet peeve for me since the massive group 3 discussion. I think we may be OK because we do seem to be in a situation where advanced textbooks give a correct statement: Greenwood and Earnshaw gets things right and carefully avoids mentioning differentiating electrons on pp. 22–3 where it discusses the building up, and I already quoted how Feynman deals with it (yes, it's a physics textbook, but the build-up of the PT is basically at the intersection of chemistry and physics). So I think we will be fine if we talk just about the configurations but somehow avoid saying that the block is actually given by the differentiating electron. Indeed perhaps it's best to simply waffle and follow Greenwood and Earnshaw's vague statement "there is a direct relation between the various blocks of elements in the periodic table and the electronic configuration of the atoms it contains; the s block is 2 elements wide, the p block 6 elements wide, the d block 10, and the f block 14, i.e. 2(2l + l), the factor 2 appearing because of the spins", without actually defining what the blocks are because nobody seems to agree on that. Yes, it kind of sucks, but policy is an important concern. If the literature needs to buckle up and define all this properly, that's not something we can do for them. ^_^

I agree that what is really needed first is some background on atomic structure. And yes, don't worry, I know what I've written is just a plain first draft. It can change a lot; I just thought getting something out would be better than just discussing in circles with nothing getting done. I will work on a draft of the Overview + Background more or less following your ideas. ^_^

The La vs Lu issue is mostly covered in Group 3 element; I think that's an OK place for it because you can't avoid it there. With regard to the textbook thing, this is quite split and La no longer has a majority. (Current split of textbooks in 2010s according to IUPAC survey is 48% La, 18% Lu, 33% compromise form with all lanthanoids under Y.) And I am not sure how many of the textbooks actually explain themselves here or focus on the issue or even talk a lot about the lanthanoids at all. So I still think we should in fact be looking at the articles specifically arguing about it. Double sharp (talk) 09:13, 18 October 2020 (UTC)

OR, SYNTH and DUE

@EdChem, Double sharp, and YBG: I have no concerns about any of these, as far as postings on this page go. The latter live or die according to their reception, here. I'll qualify that by saying our project is very small and sometimes, IMHO, good ideas get stuck due to personal, irrational dislikes (which have no place in an encyclopedia) rather than any basis in scientific merit, no matter how many supporting sources are provided. I've posted about this previously. But that's life; you have to manage it and learn from it, as best you can; it's likely no different in other forums; and how people feel or think can enrich your own perspective on whatever it is that is being discussed. There is WP:RFC in any event which I'd never chance my arm on without first testing the water, including here and with other chemists, physicists, scientists, and in other forums.

WP:IAR. I'm more interested in WP:IAR, in pursuit of a better encyclopedia. The quality of an encyclopedia doesn't rest on quoting WP policy to one another. Much more relevant is Misplaced Pages has no firm rules:

"Misplaced Pages has policies and guidelines, but they are not carved in stone; their content and interpretation can evolve over time. The principles and spirit matter more than literal wording, and sometimes improving Misplaced Pages requires making exceptions. Be bold, but not reckless, in updating articles…".

This is particularly relevant, I feel, in chemistry, where there is much fuzziness not helped by the disinterest of the IUPAC, when it comes to terminology. Principles, spirit, and knowledge gathering and summarising are what count, rather than quoting WP policy.

Obfuscating knowledge. A particular peeve of mine is seeking to hide knowledge that exists in the literature on the grounds that explicit consensus is lacking in the literature. These are some of the most interesting aspects of chemistry IMO, and they deserve ventilation. If we'd still been hiding behind a say-nothing do-nothing see-nothing approach our metalloid article would still be subject to repeated back and forth editing as to which elements are metalloids. If there is no explicit consensus in the literature I seek to accomodate that fact in the best, most pragmatic way I can, consistent with the principles and spirit associated with improving Misplaced Pages, as an encyclopedia. That is the commendable approach the founders of our colour category periodic table took in 2003, in the absence of complete consensus in the literature, and in the best tradition of encyclopedia building.

Irony. In writing all of this I realise the irony of myself quoting WP policy. I plead making an exception in this case since the policies I refer to are antithetical to interpreting other WP policies in black letter law fashion.

Categories. On categories, we have some kernels of agreement. I support YBB in merging AM and AEM; Double sharp has expressed some support for this; R8R is not keen. On splitting the reactive nonmetals, I support this, Double sharp too, and R8R has expressed in principle support. YBG is not keen since he is interested in reducing the number of categories per 7±2. EdChem, I see you don't have a strong view on it beyond that the lens to examine it from is (IYO) how it assists / supports readers, which I agree with. So there is some reasonable support, with a few o/s concerns. Sandbh (talk) 03:07, 18 October 2020 (UTC)

R8R

I would like to clarify the part in which I am mentioned. What I said about the reactive nonmetal division was said three years ago, and I have not renewed my opinion on it since then. It could be that my opinion would be the same today and it could be that it would not if I were to look into it anew.

The more I think about the proposed division that's on the table right now, moderately active nonmetals+halogen nonmetals, the less appealing I find it. The most serious problem with it that I found is that "halogen nonmetals" can be confusing, especially in the way legend is construed now; it's not even clear that we're talking about halogen nonmetals, it seems we're talking about halogens, all of which fit into the set of nonmetals. That is confusing, and I've been thinking about it like that more and more; the final snap for me was the comment made by DePiep above, in which they ask when we agreed that astatine was not a halogen anymore. The present legend seems to imply precisely that. We didn't really agree on anything of the sort, and the legend doesn't want to imply that, but if DePiep, who's been watching this discussion since the very beginning, missed this point (DePiep is not to blame on this: it really is confusing), then what should we expect of a common reader who has not watched this discussion? I wouldn't expect anything other than thinking that astatine is not a halogen, period. Or maybe DePiep didn't actually miss anything and I am the one who missed something? One way or another, the proposed legend raises too many questions.

To wrap it up, I'm not sure if I think reactive nonmetals should be split (maybe so and maybe not), and I definitely don't think that the moderately active nonmetals+halogen nonmetals will work fine.--R8R (talk) 10:33, 18 October 2020 (UTC)

@R8R: The common reader will have effectively no idea what e.g. AM, or AEM are, or halogen N, for that matter. There may be a few who have heard of older "halon" fire extinguishers, and perhaps read the label and noticed a reference to e.g. chlorine or bromine. There is effectively nothing to confuse the common reader. As for astatine, effectively none of them will have heard of it. I once again note the references in the literature to the less active, moderately active, and highly active nonmetals, and that a chemist, who has written about nomenclature, suggested the name moderately active nonmetals to me. Here are the examples again:

• Timm (1950): "Oxygen is a moderately active nonmetal and will combine directly with nearly every other element to form an oxide.
• Gelender at al. (1959): "This oxidation may be accomplished by: (a) The use of suitable oxidizing agents for moderately active nonmetals."
• Perlman (1970): "Between Groups I and VII there are gradations from active metals (Col. I) to less active metals to moderately active nonmetals to volatile nonmetals (halogens Col. VII)."
• Wulfsberg (2000): "Most of the moderately active metals and nonmetals (the electropositive metals and electronegative nonmetals) are reduced from their oxides…using carbon."
• Welcher (2001): "The elements change from active metals to less active metals, to metalloids, to moderately active nonmetals, to very active nonmetals, and to a noble gas."
• Sorokhtin at al. (2007): "Nitrogen is a moderately active element, reacting weakly with natural inorganic compounds."

The lengths you will go to in avoiding or ignoring literature, even if it is ugly, are extraordinary. Sandbh (talk) 04:17, 20 October 2020 (UTC)

@Sandbh: And where are the indications that these are anything other than adverbs and adjectives modifying a noun? Are "moderately active nonmetals" in the indexes of these texts, if they have them? And where are the clearly stated definitions that these refer to {H, C, N, O, P, S, Se} only? And supposing that it is terminology, exactly how widespread it is in textbooks?

It's not about "avoiding or ignoring literature". It's simply a question: how major is this POV? What is the WP:DUE weight that should be accorded to it? Is this a major thing that most chemists would understand, or is it closer to the kind of support I can produce for putting helium over beryllium in the periodic table: a handful of journal articles that so far almost nobody listens to? What is the prevalence of this term in the literature? Out of a general sample of sources, how many of them use and define this term as a term? And how does that percentage compare with the percentage of sources drawing the periodic table as Sc-Y-Lu? Double sharp (talk) 09:18, 20 October 2020 (UTC)

@EdChem: I believe User:R8R, User:Sandbh, and I are having a disagreement in this section that you could help with by providing a perspective. ^_^ Double sharp (talk) 09:20, 20 October 2020 (UTC)

Since the term moderately active nonmetals was suggested to me by a chemist, in preference to light nonmetals, I'd expect most chemists would understand it. Consider how the halogens are referred to in the literature:

"Young (1976) : …the strongest nonmetals, as we have seen, are the halogens."

Dorin (1982): "Because of relatively high nuclear charges and small atomic sizes, members of the halogen family, Group 7A, are the most active nonmetals."

Cotton & Wilkinson (1999): "With the exception of the Li–Cs group there are closer similarities within the group than in any other in the Periodic Table."

Jaffe (2012) :"The extremely active non-metals, fluorine, chlorine, bromine and iodine, all appeared in the seventh group."

Powell (2013): "Chlorine, bromine, and iodine are far less reactive than fluorine but are still very active chemicals."

What about the metalloids?

It has been known for over 120 years that metalloids have a predominately nonmetallic chemistry (Newth 1894; Friend 1914).

"When atoms have their outer shells just over half filled, they are thought of as nonmetals, but they are so near the border line that they are weak nonmetals." (Eby et al. 1943, p. 404)

"The elements near the dividing line are only weakly metallic or nonmetallic." (McCue 1963, p. 264)

Brinkley (1945, p. 378) writes that boron has weakly nonmetallic properties.

"With weakly electronegative elements like boron and silicon…" (Hurd 1952, p. 62)

"…while the oxides of the metalloids will tend to be amphoteric or weakly acidic" (Swift 1957)

Glinka (1965, p. 88) describes silicon as a weak nonmetal.

Rochow (1966, p. 4) noted metalloid compounds are always less acidic than the corresponding compounds of the nonmetals.

Vernon (2020; that's me): "Setting aside the confusion surrounding the metalloids, they are here treated as chemically weak nonmetals, consistent with Hawley’s Condensed Chemical Dictionary (Larrañaga et al. 2016, p. 988); see also Dingle (2017) for a refreshing interpretation of the status of metalloids, as ‘poor non-metals’."

And what about still more on the strong-moderate-weak-moderate-strong progression across the periodic table(?);

Emerson (1944): "The table shows the continuous variation of properties from active metals to active nonmetals as electrons are added to the outer shell of the atoms "

Gregg (1961): The electropositive elements are on the left side of the chart and the electronegative elements on the right. In any given horizontal row of representative elements, the alkali metal element is the most electropositive element, and the halogen the most electronegative. Elements midway between these two extremes are relatively weakly electropositive and relatively weakly electronegative."

Beiser (1968): "Across each period is a more or less steady transition from an active metal through less active metals and weakly active non-metals to highly active nonmetals and finally to an inert gas."

Booth & Bloom (1972): "A period represents a stepwise change from elements strongly metallic to weakly metallic to weakly nonmetallic to strongly nonmetallic, and then, at the end, to an abrupt cessation of almost all chemical properties."

Etkin (2019): "This corresponds to the experience according to which in each period there is a transition from active metals to less active, and then from active non-metals to very active non-metals. Moreover, at the end of each period (with the transition to inert gases)…"

Like the lanthanides, actinides, transition metals, and metalloids there is no clear, universal definition of the nonmetals involved. There is however a default defintion: They are the nonmetals left over when the noble gases, halogens, and elements most commonly recognised as metalloids are set aside.

Same goes for the fuzzy PTM, they are the metals leftover after the AM, AEM, Ln and An (however defined), and transition metals (however defined, noting e.g. Rayner-Canham only counts groups 4 to 11, as such) are set aside.

In the literature, the PTM have 17 alternate names that I'm aware of. The nonmetals lying between the metalloids and the halogens have at least seven names by which they've been referred to and this number will soon go up to 12+. Possibly the most encompassing term, which has fuzzy boundaries, is life elements:

"The third lecture can be a breath of fresh air or a shaking of foundations for the biochemist, as Steiner discusses the life elements, carbon, oxygen, hydrogen, nitrogen and sulphur in Nature's household." (Storl 1979)

"Life elements | Most matter in living cells is four of the lightest, simplest elements. In organisms, 95% of the atoms are, in order of amount: hydrogen, oxygen, carbon, and nitrogen. These four organic elements are most of life's physical substance. (Goreau et al. 2014).

"Unlike other essential life elements H, C, N, O, no appreciable amounts of gaseous phosphorus compounds are… (Corbridge 2016).

"Major forms of life elements For all organisms, the major chemical elements are H, C, N, O, P and S, forming the majority of the organic components in living organisms." (Zhu 2020).

Same goes for the "building blocks of life":

"…of carbon and on the interaction of macromolecules made of six biogenic elements (H, C, N, O, S, P ) which together…Great progress has been made in demonstrating that the building blocks of life can be synthesised in the laboratory. (British Interplanetary Society 1985)

"More than 90% of the known universe is made up of hydrogen, whereas the other four major molecular building blocks of life, oxygen, carbon, nitrogen, and phosphorus…" (Piantadosi 2003)

"Building blocks of life | Life is based on complex chemistry yet only a few of all the available elements participate in most life-supporting reactions on Earth: carbon, nitrogen, oxygen, hydrogen, phosphorous, and sulfur." (Schulze-Makuc 2006)

"Carbon (C) and nitrogen (N) are the building blocks of life on earth." (Neider 2008)

" …possibly including the first chemical building blocks of life, exist in comets and may have been carried by them, like the wind ... One element of the six, crucial for the origins of life (H, C, N, O, S, and P), phosphorus (or a phosphor-containing…" (Thomas et al. 2013)

As noted many times, H, C, N, O, P, S, and Se are the only elements (on WP) each having their own biogeochemical cycle article.

Probably, I haven't looked too closely at this, references to these seven nonmetals, by way of their numerous collective terms are at least as popular as "alkaline earth metals".

I surmise the reason why there is no one standout collective name for them is that their properties of interest fall across so many disciplines, including general chemistry, biochemistry, metallurgy, cage compounds, crystallography, energetic, geochemistry, organic chemistry, hydrogen storage, materials science, mineralogy, nano-chemistry, spectroscopy, and X-ray imaging.

Meanwhile, here we are knocking ourselves out in a WP:POLICY cite festival; striving to attain unattainable consistency and terminology standards which just don't exist in chemistry; and doing everything possible to avoid building a goddamn better encyclopaedia, never mind all the information is out there, anchored in the literature!

I'll include a little more about this, later on. Sandbh (talk) 07:24, 21 October 2020 (UTC)

Sandbh, could you maybe stop attributing motives to other editors in a content discussion? Above you said to User:R8R The lengths you will go to in avoiding or ignoring literature, even if it is ugly, are extraordinary. After that User:EdChem talked to us about this when it happened between us, but now immediately above you said we are...doing everything possible to avoid building a goddamn better encyclopaedia. If you have behavioural grievances with me, or with R8R, then can we please follow EdChem's advice and bring it to an appropriate venue for that sort of thing, instead of mixing it in the middle of a content thread? Double sharp (talk) 13:43, 21 October 2020 (UTC)

Double sharp Thanks for asking. I'll probably decline your request although I'll keep it in mind. I say this in the context of DePiep's benchmark contribution to WP:ANI, no less, i.e. "You damned fucking STARTED this fucking ANI thread R8R." In that context, what I say is a whimper.

The issues I perceive and raise are pertinent to our content contributions, as a project team, so I'll continue to post that kind of thing whenever or where ever I deem it appropriate. Yes, as I've posted before, all of this is about content, based on the goddamn science, never mind whether or not we like the outcomes of that science, according to out personal preferences, which rarely have any relevance here, but people keep hiding behind them. Another pet peeve is invoking a prefernce for symmetry, which is culturally-biased phenomenon, rather than having a basis in science, to guide one's decisions here. I'll keep calling out that one, whenever I see it.

As far as R8R is concerned, getting him to move an inch is like asking him to move a mile. For that matter, I can't recall R8R *ever* supporting a proposal for change raised within our project. If I'm wrong, I'll take it back. That's how it feels like to me, is all I'm saying.

I am calling out these behaviours since nothing else seems to work. I know what this is about. It's like overcoming the perceptual filtering of e.g. rusted-on Trump supporters (no offence intended). It's a waste of time, since they ignore, filter out, or twist anything at odds with their values-beliefs-rules framework, which is on autopilot. Essentially, I can only appeal to the middle ground, and hope there are enough "votes" to swing the balance. Sandbh (talk) 06:26, 22 October 2020 (UTC)

@EdChem: Just drawing your attention to this for your view.

@R8R: And yours too, since it relates to you. Double sharp (talk) 08:45, 22 October 2020 (UTC)

Thanks for pinging me. Sandbh, there is a difference you do not seem to get: the purpose of WP:ANI is to address behavioural issues, including pointing out self-serving hypocrisy. Talkpages OTOH, like article ones and this one are explicitly not open for behavioural problematic edits. Instead, they are for content-related discussions. And that is what POLICIES you are invited to follow, aim at. -DePiep (talk) 12:41, 25 October 2020 (UTC)

@Sandbh: A few things that may need clarification:

I clarified my position on what I treat the common reader like not too long ago, but I may need to clarify it further to reflect my thoughts more accurately. In contexts that I believe to be interesting for people without any chemical knowledge (our most popular articles like iron or aluminium), I assume no knowledge on the part of a reader. In contexts that are plainly dull for such people (group 3 element being one obvious example), I assume some knowledge because I don't believe that those people who could read it will not know it. Generally, I assume as little knowledge as I believe a person who could read this article or part of an article could have. The part about classification of the elements obviously requires some basic knowledge of what elements are. Perhaps a few months into the school chemistry course is enough.

Here's a quote I just found online:

Ndlovu, Simate, Matinde (2017) "From the chemistry point of view, copper is a moderately active metal" -- why are we ignoring this category and not including "moderately active metals" into our fold? Let's say the concept of transition metals were not a factor, should we rely on quotes like this to include this name? My answer would be no, because this is not meant as a single term, but rather a term with a qualification. I view "moderately active nonmetals" similarly. In any event, it's not this part that is the problem, after all, "reactive nonmetals" does precisely the same. The confusing part about halogens, that's what's confusing here. I said it clearly already, but I hope it's clear now.

Another point that may need clarification is this: I am trying to build a better encyclopedia, and I'm sure Double sharp is, too. My (and Double sharp's) understanding of what helps achievement of this goal may differ from yours. That's fine, that's what discussions are for. In this beautiful language that you speak and I attempt to speak, there's the magnificent concept of "contest of ideas," something that does not have nearly as much currency as in my own mother tongue. I suggest embracing that. For that matter, that's how I view our discussions. I never expect anyone to move simply because I know better. I'm not entitled to that and neither is anybody else, but I could try to convince them with what wit I can master. It's either consciously trying to build a better encyclopedia or giving way to something you don't believe to fulfill this goal. Often, there can only be one, and in such cases, I pick the former (and I expect anyone else to do the same). For a while, I've been pondering whether it doesn't matter (in which case I wouldn't care much) or that it does because the halogen bit is confusing, and I've settled on the latter.

For that matter, during the last group 3 discussion I chose the version that I thought was better for the encyclopedia, even though I went against my personal preference. (The point about me not supporting a change is rather strange -- I've supported -Lu-Lr almost since the day I came to this project, even though it was -*-** (-La-Ac in our PTQ, which was an image back then) back then, and I was the one to propose "reactive nonmetals." I get it it may feel like it but that's why one normally need hard evidence to back up whatever you feel to ensure their feelings are justified; "selective perception" is an interesting phrase you brought up.)

I hope we can wrap it up at this point and get back to discussion on encyclopedic topics at hand.--R8R (talk) 13:10, 25 October 2020 (UTC)

@R8R: Thanks. My comments follow. Noting your closing comment, if I feel a need to continue discussing this interesting topic, as opposed to starting an RFC at the periodic table talk page, I’ll start a new thread.

1. Regarding the common reader, I make no assumptions about what they may or may not know, nor their motivation for looking up or reading any particular article. An encyclopaedia is an encyclopaedia. We are not in the business of second-guessing the nature of individual readers, nor their motivations. What one will find familiar another will find boring, and vice-versa. It’s none of our concern. A quality encyclopaedia focuses on consistency of its articles and a consistent reading level approach, that’s all.

2. We do not include a category of moderately active metals because the “transition metals” category is about 30,000 times more commonly encountered in the literature. If there was no such thing as a transition metals category I expect we would look at what terminology the literature uses to refer to the metals involved, and choose a category name on that basis. We took the same approach with the PTM category name.

3. There is nothing confusing about “halogen nonmetals”, given we chose to colour categorise astatine, having regard to the literature, as a PTM. Astatine is still a halogen according to IUPAC, of course. Cleary, some halogens are nonmetals, and at least one is a metal. So what? The confusion you are concerned about is a manifestation of what I wrote about before i.e., “…we are knocking ourselves out…striving to attain unattainable consistency and terminology standards which just don't exist in chemistry”, rather than focussing on what the science tell us, as per EdChem’s suggestion (and I include classification science here), even if we find the outcome to be unpalatable or ugly, according to our subjective personal experiences, which have nothing to do with science, per se, nor with an encyclopedia.

4. I agree that you and Double sharp, and I, are committed to developing a better encyclopedia.

5. It occurred to me that our encyclopaedia has > 6,000,000 articles. I presume there would be room in such an encyclopaedia for an article on halogen nonmetals, and another one on moderately active nonmetals or another equivalent from the dozen or so alternatives there are. Certainly there would be no shortage of literature to draw on; ditto metalloids, and noble gases. Oh, not forgetting that “moderately active nonmetals” was suggested to me by a non-WP editor chemist who has written on nomenclature matters. Sandbh (talk) 09:27, 28 October 2020 (UTC)

EdChem

Sandbh, IAR is both a valuable and a dangerous policy. As an example that applies to none of us, suppose editor X is topic banned from area Y... X is convinced that they are better at writing content in topic area Y and so ignore the topic ban and continue editing, invoking IAR as justification. How well do you think X's argument would stand up when it got to ANI? I would say the time taken for a block to be imposed would be measured in minutes, and not very many of them. Editors who try to use IAR to get around policy can run into trouble similarly quickly. Arguing to IAR-override DUE, for example, because one paper says A while every textbook says B is unlikely to fly, even if B is true and corrects a long-standing incorrect belief in A. Encyclopaedias are not supposed to be at the cutting edge of knowledge, they lag behind waiting for debates to resolve. You state that Principles, spirit, and knowledge gathering and summarising are what count, rather than quoting WP policy, but when IAR speaks of principles and spirit it means those that live in policy. Knowledge gathering and summarising are good, so long as they don't move into SYNTHesising conclusions not previously made or offering a summary that goes beyond extant knowledge into OR. The spirit and principles of those policies is about encyclopaedias summarising what is known and not including what is new, so IAR will not support going beyond that which is published in RS. I'm all for IAR to facilitate editing in line with spirit of policy, but not for avoiding policy. EdChem (talk) 10:38, 18 October 2020 (UTC)

EdChem I basically agree, with some observations. I don't regard IAR as dangerous. You do, that's fine. There is no rule or law that says, "Encyclopaedias are not supposed to be at the cutting edge of knowledge" although if that's a belief that works for you, that's fine too. As a living encyclopedia I see WP having the potential to be at the cutting edge of knowledge, where such knowledge refers to what is known, with a reasonable, plausible, context relevant, interesting, or potentially interesting degree of reliability. Anything short of that is un-encyclopedia, in the broadest sense of the meaning of encyclopedic, in my view. Too, policy is only ever supposed to be a guide to subjective decision-making, having regard to applicable circumstances, and higher contextual values, (the five pillars in the case of WP) rather than a set of rules, although many people interpret and apply policy as a set of rules. Sandbh (talk) 02:03, 19 October 2020 (UTC)

Double sharp

I've shifted my support to blocks alone, actually. Double sharp (talk) 10:20, 18 October 2020 (UTC)

Sandbh It is not about hiding knowledge. It is about policy. We are supposed to be following the literature. Not leading in it. If the literature is fuzzy, then we should say that it is fuzzy and not try to make it look less fuzzy than it is. If there is no standard term for something, then the right option for WP is not to pick out the one that looks nicest, it's admitting that there is no standard term. As WP:UNDUE puts it paraphrasing Jimbo:

Equally, it's not about "basis in scientific merit". It's about whether there is a genuine agreement in the relevant sources; if there is, then we can say it. And if there is not, then we should be focusing only on mentioning the major viewpoints, and weighting them according to the most relevant sources. And it's not about "personal, irrational dislikes" as you write. You can argue as much as you like. So can I, so can anyone else. We can all try our best to persuade others. That's just as in Misplaced Pages:Consensus#Through_discussion. But if you can't persuade others, you can't force them to agree with you. That does not mean they are opposing just because of "personal, irrational dislikes". Double sharp (talk) 15:02, 18 October 2020 (UTC)

The actual formal group 3 proposal

Should the periodic table on WP be presented in this form (Sc-Y-La):

or this form (Sc-Y-Lu)?

Note that this is not going to be about the categorisation. The only topic I plan to have discussed here is the group 3 issue.

• A question, for clarification: these are navboxes, so on a tertiary presence level (they don't even show in mobile view). I assume the proposal is to apply this note to ~every PT at enwiki, especially the top ones. (Exceptions needed? I think we can even manage to add this to the micro one :-) ). -DePiep (talk) 15:51, 18 October 2020 (UTC)
  • @DePiep: Yes. ^_^ Double sharp (talk) 16:17, 18 October 2020 (UTC)

Added later: the precise wording of the footnote is open to discussion, and the important thing is just that there be one. So even if you don't like the footnote in either option, you can first write which form you prefer to have in terms of the main PT, and afterwards discuss how to change the footnote. The important question is which form you support as the main one and relegating the other to the footnote. Double sharp (talk) 00:04, 19 October 2020 (UTC)

Idea: we could repeat (copy) the "3" group header in both places, whichever outcome. Visual aid, makes the footnote easier & shorter. -DePiep (talk) 16:45, 20 October 2020 (UTC)

@DePiep: Do you mean to have the 3 group header also atop La and Ac? I worry that this may confuse the situation being shown. In the first table above Sc-Y-La is shown and Sc-Y-Lu is correctly described in the footnote; in the second, they are the other way round. But if we duplicate "3" above La and Ac we end up showing as the primary thing what looks like the "bifurcated group 3" option which is quite rare and not one of the options IUPAC says it'll decide on.

This said, a possible idea I had in cases where there may not be space for a real footnote is to have a tooltip. So you'd mouseover the "3" and it'd give you the footnote even when there's no space for it. I am honestly not sure how it'd work for the micro PT because there not even the element symbols, much less the group numbers, are there. But we can decide on all that afterwards. Double sharp (talk) 23:21, 20 October 2020 (UTC)

Yes, is what I propose. One can not "clarify & explain" this in just a textual footnote. Graphs should help. And no, no bifurcation in play (C'mon). Once we decide to present the two-way-PT, there are consequences. Major consequence is: we must accept to show an ambiguous graph. I'm fine with that, and will push the ambiguity clarify it, graphical ways included. Go full double-form. -DePiep (talk) 23:44, 20 October 2020 (UTC)

@DePiep: Well, I agree with you that there should not be bifurcation in play. That's why I'm wary of anything that makes it look like that. But, again, we can decide all about such issues on the footnote once we've established what to show as the main thing and what to show in the footnotes. I would like to clarify the discussion flow by focusing on one thing at a time here, if that's alright with you. ^_^ Double sharp (talk) 23:54, 20 October 2020 (UTC)

Opinions

Requested from @R8R, YBG, DePiep, Droog Andrey, ComplexRational, Sandbh, Officer781, and EdChem: who have discussed things on the ELEM talk page recently and are still active. Double sharp (talk) 15:20, 18 October 2020 (UTC)

Sandbh could you give a wlink or two for me to read? As in: 'this describes my approach well'? -DePiep (talk) 16:23, 18 October 2020 (UTC)

DePiep let me see what I can come up with. Sandbh (talk) 08:22, 19 October 2020 (UTC)

• Very Strong Support for Sc-Y-Lu, for reasons set out below. Briefly: IUPAC is going to make a decision, but has not done so yet, and we have no idea when they will. So I feel we should look at the fact that most sources focusing on the group 3 issue are in favour of Sc-Y-Lu and give lots of scientific arguments for why, and that this choice has gotten into a significant number of standard textbooks and popularised treatments of the periodic table for laymen. The facts that the previous IUPAC decision in favour of the compromise Sc-Y-* (now it seems to be overturned by a new project relooking at the issue) appeared to admit that Sc-Y-Lu was better as well as a minor ancillary argument in its favour in my opinion, as is the fact that the latest 32 column periodic table shown in a IUPAC Red Book is Sc-Y-Lu, but to me these are the weaker arguments. Double sharp (talk) 15:15, 18 October 2020 (UTC)
• Support for Sc-Y-Lu. Droog Andrey (talk) 16:58, 18 October 2020 (UTC)
• Comment moved below under § Moved from Opinions to Supplements YBG (talk) 02:23, 21 October 2020 (UTC)
• Neutral, with a comment. (ec) I am neutral re Lu or La, because I cannot weight the scientific arguments & sources brought into this. However, for the encyclopedia I make this claim that "The Footnote" re group 3 be improved, and be systematically the same throughout all articles and PT templates. For example, the sup link should be the same everywhere duh. Also, there must be a wikilink to section say "]" (or whatever single point to link to), that addresses this issue from the top. Why is there no article Periodic table Group 3 issue anyway?

So: up to a generic and good group3 text & link. -DePiep (talk) 22:36, 18 October 2020 (UTC)

• @DePiep: There's no article but there is a section: Group 3 element#Composition of group 3. Indeed, we can improve "The Footnote". EdChem and I have been discussing how to do it. ^_^ Double sharp (talk) 22:41, 18 October 2020 (UTC)
• There once was such an article, DePiep. EdChem (talk) 22:51, 18 October 2020 (UTC)

• Eh, don't blame me but just improve the proposal then (puh-lease). And since you both understand and agree, let's do so along the main line & intention I described. -DePiep (talk) 22:58, 18 October 2020 (UTC)

• Not blaming anyone. Here is the merge discussion – not much participation – but I have wondered whether a stand-alone article is a sensible way forward (though a better one than the one that was merged). EdChem (talk) 23:04, 18 October 2020 (UTC)

• Is not my problem, is not the issue. Again, I seriously propose to make this footnote be: more to the point (spell out IUPAC, really?), the same line structure everywhere, use the same visual representation enwiki wide. So: same everywhere. -DePiep (talk) 23:24, 18 October 2020 (UTC)

• • Anyway, to keep things clear, I guess we could wait and see what consensus develops before deciding how the footnote is going to read. ^_^ I'll add a brief note above saying that the exact wording of the footnote can be subject to future discussion, but there will be one. Double sharp (talk) 00:02, 19 October 2020 (UTC)

• Support Sc-Y-Lu for reasons mentioned in previous discussions and described here by Double sharp. I've said my piece before, and I haven't read anything or otherwise had reason to change my opinion. I simply am more convinced by the block and periodic trends arguments described for Lu-Lr in the literature; if I find what I wrote before, I will repost it. (I apologize for not having followed the whole thread.) ComplexRational (talk) 23:57, 18 October 2020 (UTC)
• Oppose a change, at this time. ​​​​​​​​

  Briefly:

  1. the relevant IUPAC committee may or may not accept the report of the Group 3 project;
  2. as such, there are no plans for the relevant IUPAC committee to draft a formal recommendation and seek input from the chemistry community;
  3. Sc-Y-*-** is NOT due to be deprecated—that will be matter for discussion within IUPAC as a whole, since the periodic table appearing in The Red Book is simply that used within IUAPC rather being formal recommended by IUPAC for external use; and
  4. IUPAC has never decided in favour of any form of table—I’ll expand on this later.

  More details moved below in § Details of Sandbh's opinion and ensuing thread. YBG (talk) 01:39, 23 October 2020 (UTC)

  --- Sandbh (talk) 01:15, 21 October 2020 (UTC)

  Double sharp's response and Sandbh's replies moved below (in § Details of Sandbh's opinion and ensuing thread). YBG (talk) 01:39, 23 October 2020 (UTC)

• Support Sc-Y-Lu due to: (1) more pleasing esthetics; (2) greater consistency with the Aufbau principle aka Mandelung rule, a good first-order approximation that gets stressed as orbital energy levels grow closer and then crumbles in the face of relativistic effects; (3) closeness to Janet's Left Step periodic table; (4) Apparent increasing RS support per Double sharp. My opinion is swayed by (1)>(2)>(3)>(4), contrary to WP policies, but there you have it. I will loose no sleep if we keep Sc-Y-La until we know IUPAC's decision and the reaction to it. Let's reach a decision quickly, lest our energy and creativity is redirected away from WP improvements we all agree on. YBG (talk) 05:42, 19 October 2020 (UTC)
  • @YBG: Well, (2) also seems like a legitimate reason; if we are going to discuss the Madelung rule in the context of the PT like many sources do, then it makes sense for the PT we display as primary to actually follow it. So, don't worry about it. ^_^ Double sharp (talk) 08:58, 19 October 2020 (UTC)

• IIIB or not IIIB? I was taught (it was when Methuselah was still a lad) that it was Y-Sc-La. IIRC, that's what Cotton & Wilkinson said. I only recently became aware of the Sc-Y-Lu suggestion through one of those Periodic Videos.

I have no opinion on the current scientific consensus (if any), and am not going to trawl through the citations for and against the positions. As an organic chemist, I have zero interest in the less fashionable parts of the periodic table anyway.

What I do know is this: WP:RS, in particular WP:SOURCETYPES. WP's voice should say what the current consensus, as described in modern editions of advanced textbooks amd review articles in respected general-interest scientific publications, is. We can (and should) describe the La/Lu debate and arguments. We should absolutely not take a position on it. That would be WP:OR. Narky Blert (talk) 19:17, 24 October 2020 (UTC)

@Narky Blert: First of all, thank you for your comment. I greatly appreciate your perspective as a chemist and as an experienced Wikipedian. And yes, I guessed that this is not exactly a hot-button issue among those whose specialty isn't the rare earths. ^_^ So I am going to reply to your third paragraph, which I definitely agree with, to clarify what I meant as the starter of this thread.

As the starter of this thread, I want to clarify that I have no intention to have WP take such a position. That's why I don't like the current situation at templates like {{Compact periodic table}} where the La form is simply presented with absolutely no indication that there is any controversy: it feels to me too much like taking a position. Likewise I don't like what it used to show before that, which was the Lu form with no indication either. The issue extends further to places like List of chemical elements where the group for La is simply listed as "3" with no indication at all that this is controversial. I think most of us agree here that since there is a controversy that has gone up to IUPAC, WP has to reflect its existence, and not make it look like there is one agreed version when there isn't. So these two above are my proposals for how {{Compact periodic table}} looks, either of which I think would improve the template.

Out of various possible ways I considered to show the issue, I thought the two above were best, putting one option in the main table but always taking care to put a note saying that there is another. Because this way (1) the other option is always clearly presented in a footnote summarising the dispute, (2) it avoids duplicating the rest of the table which is identical, and (3) it's already in use on Polish Misplaced Pages, suggesting that it should not be too far off from general WP norms to do it this way. I didn't think showing 2 tables all the time was a good idea (because apart from where Sc and Y and the group 3 label appear, they are identical in every other way, and it really doesn't seem that sensible to me show 2 PT's when the PT is to be presented in an article describing, say, some topics in organic chemistry where the rare earths are of very little interest), and I also didn't think duplicating Sc and Y in one table was a good idea (because that makes a new graphic form appear that is hardly if ever used). So, that is why the options are as above: I couldn't think of anything better, and Polish Misplaced Pages using it made me think that English Misplaced Pages would probably also be fine with something like it. That being said, if you have another suggestion for how we could reflect this issue in a policy-compliant way, I should like to see and consider it! And if you don't, no worries; your comment here regarding WP:RS is already greatly appreciated by me. ^_^

So my question and survey here was intended to ask for opinions regarding whether it better reflects the source situation to show La as the main one and Lu in the footnote, or Lu as the main one and La in the footnote. Not which is scientifically better, which is not a question relevant for making a WP decision indeed. I thought that would be clear, but in retrospect given some issues wrt respect for policy that have arisen at the project, I should probably have made it clearer. (That's an issue I currently have with a single editor User:Sandbh, and should be if I understand correctly be discussed at the ANI thread I currently have open rather than here.) At least, I am just using "Support Sc-Y-Lu" as a shorthand for "Support showing the Lu form as primary with a footnote explaining that La sometimes appears there"; I cannot speak for the others supporting it (@Droog Andrey, ComplexRational, and YBG:), but I think (and hope) that that is the general idea among them too. Double sharp (talk) 21:54, 24 October 2020 (UTC)

@Narky Blert: Well put.

The most popular form of the periodic table is the one with La in group 3.

The Polish periodic table sort of acknowledges this too, where it notes: "Alternatively, scandlers often include not lutetium and lorens but lanthanum, actinium and the hypothetical unbiun."

Possibly the reason why they show Lu in group 3 is erroneously set out in their article on the group 3 elements. This article says, in part, "IUPAC includes lutetium (Lu) and lorens (Lr) ." This is nonsense; IUPAC has never taken a position on group 3. None of the three listed citations say this.

Note the main table in their periodic table article uses the IUPAC format.

--- Sandbh (talk) 03:37, 25 October 2020 (UTC)

I thought of proposing a straw poll of Martyn Poliakoff's ties, but concluded it would be WP:OR. Narky Blert (talk) 10:46, 25 October 2020 (UTC)

• Oppose for the time being. My reasoning can be found below.--R8R (talk) 15:42, 25 October 2020 (UTC)

Supplements

Anyone can write a long wall of text here supporting a position. I prefer the opinions above to be kept short (one paragraph of justification, maybe) to avoid confusing the issue, but here we can go on as long as we want. Double sharp (talk) 16:38, 18 October 2020 (UTC)

Long justification by DS for his !vote

When asking this, we need to look at reliable sources by policy. So what do the most reliable sources say? Here's my view. In contrast to my previous postings on it, I am not going to mention the scientific arguments at all because they are not relevant for WP: only the sources.

IUPAC

Well, there's the rub. They haven't exactly decided. Since 2015 they have had a project specifically to deliver a recommendation on which it should be. Some sporadic progress updates have been posted, but there is no indication on a time schedule. Given that IUPAC has not actually approved any form of the periodic table (link is to their website), this is maybe not surprising.

Now, it is true that they currently do show something. They show a compromise form with all fifteen lanthanoids, and all fifteen actinoids, in group 3 below yttrium. The only trouble is that if you look at their project page, this compromise is specifically not among one of the two alternatives that will be picked. All they say there is:

So, what we can say is that IUPAC has acknowledged that there is an argument and has set up a process to make a decision. In my opinion that shows clearly that we should not present any one form as if it is uncontested. The only problem is whether to make it:

1. Show La as default, with Lu footnoted as a version some advocate; or
2. Show Lu as default, with La footnoted as a version some advocate.

We can also ask where this compromise came from. That seems to be from the 1988 IUPAC report New notations in the periodic table prepared by Ekkehard Fluck.

The arguments for Sc-Y-Lu in the literature, judging by this, seem to have been considered convincing by an official process of IUPAC. (One may argue that Fluck prepared the report, but IUPAC also published it and others gave comments.) This is suggestive, although weak because it did not lead to its adoption. The reason for Sc-Y-* to be adopted seems to be just to compromise between this and the fact that Sc-Y-La was more common. However, that is also a bit moot because the IUPAC project is specifically not going to pick the compromise option; evidently it is not a compromise that actually made anyone arguing about this happy. So this doesn't strongly support anything very well in my opinion: surely it eventually decided in favour of showing Sc-Y-*, but apparently now this is not going to be the final decision; and surely it suggested that some people at IUPAC were convinced by Sc-Y-Lu arguments, but it didn't translate to its official acceptance. I personally read this as a point mildly in favour of us showing primarily Sc-Y-Lu over Sc-Y-La (since Sc-Y-* is due to be deprecated), but it is not the strongest one.

The report refers to the 1988 Red Book. Now, there wasn't actually one. But there was a 1990 Red Book (maybe it got delayed?), which contains 8, 18, and 32 column periodic tables. The 8 and 18 column forms shown indeed follow the compromise arrangement just as Fluck said. However, in a 32 column form this compromise is simply impossible without stretching scandium and yttrium. And lo and behold, on p. 283 it shows a 32 column table with a Sc-Y-Lu group 3. With "3, IIIA, IIIB" very clearly presented above the column with Sc, Y, Lu, and Lr, and nothing above the column with La and Ac.

The only subsequent Red Book is from 2005, and there only the 18 column form is presented: they write "Lesser omissions include ... the several different outdated versions of the periodic table." So the significance of the Sc-Y-Lu group 3 in the 1990 Red Book is in doubt, since it is for the 32 column form that they call outdated. OTOH, that 32 column form is actually still used, and our navbox templates actually show it, so it's not really that outdated. One could equally make the argument that since we show the 32 column form sometimes, and that is the latest 32 column form shown officially by IUPAC, that we should follow it. I do read this as a minor point in favour of showing primarily Sc-Y-Lu over Sc-Y-La, but again it is not the strongest one. Which is maybe not surprising because they have not recommended anything yet, so we cannot read too much into this.

A paper by Holden that was supposed to be presented to the IUPAC general assembly in 1985 clearly supports the Lu under Y option. But IUPAC has not yet officially recommended it.

Therefore, the situation with IUPAC seems to be:

• IUPAC has not recommended any particular form of the periodic table. It plans to make a recommendation on group 3, but has not yet. It currently shows a compromise form on group 3, but clearly states that that compromise will not be its eventual recommendation. In the 18 column form it continues to use the compromise while not recommending it. A report published by them admitted that for scientific reasons lutetium in group 3 is better, but did not go on to recommend its adoption. On one occasion, when they showed the 32 column form of the table they clearly showed lutetium and not lanthanum in group 3. They later called the 32 column form outdated, but we actually do use it in some places.

This suggests to me that:

• The compromise form, while having merit previously, has much less merit now because IUPAC has at least made it clear that it will be deprecated. Eventually.
• Among the other two forms, lutetium in group 3 may have a very slightly greater claim to IUPAC than lanthanum in group 3 which doesn't have any, because of the statements in the report and its appearance in the 1990 Red Book. However, neither claim is all that strong because IUPAC has not made any recommendations on the PT yet.

So IUPAC isn't so helpful as it doesn't clearly support anything at the moment. All we can get from it is confirmation that the dispute exists.

Textbooks

A IUPAC survey of textbooks shows that while the La form dominated in the past, support for it significantly weakened with the start of the new millennium. We have now reached the point where it does not have a majority. Indeed, no form seems to have an overwhelming advantage anymore:

I have given percentages that were not in the original, but that is WP:CALC I guess. It's not a full-blown statistical analysis. Although the set of texts with lanthanum in group 3 is still a majority, it has significantly lost its former plurality.

Moreover, the set of texts with lutetium in group 3 has quite a few well-known texts in it (not a complete list):

• Atkins and Jones: Chemical Principles: The Quest for Insight (2002)
• Ball: The Elements: A Very Short Introduction (2002)
• Brown et al.: Chemistry: The Central Science, 11th ed. (2009)
• Ebbing et al.: General Chemistry, 9th ed. (2009; they changed from lanthanum in group 3, which they showed in the 8th ed. of 2005)
• Jerry et al.: Techniques in Organic Chemistry, 3rd ed. (2010)
• Metcalfe et al.: Modern Chemistry (1974 and 1982)
• Jones and Atkins: Chemistry: Molecules, Matter, and Charge (2000)
• Oxtoby et al.: Principles of Modern Chemistry, 8th ed. (2016; they were already showing that way back in the 1980s)
• Rayner-Canham and Overton: Descriptive Inorganic Chemistry, 4th ed. (2006)

Excluded from the survey but also extremely well-known is

• Clayden et al: Organic Chemistry.

There is also

• John Emsley, Nature's Building Blocks (I don't know why this was included, as it's not a textbook, but it's a rather popular book on the elements for laymen; its adoption of Sc-Y-Lu shows that this would not be unfamiliar to the average person)

I think it's clear that the Lu form cannot be dismissed. It has to be mentioned in some fashion with such adopters. Of course, the La form also has very significant adopters, such as Greenwood and Earnshaw; I just list more Lu adopters to make it clear that these things do exist.

I draw from this situation the conclusion that:

• Although in the past the form with lanthanum in group 3 was overwhelmingly predominant and deserved priority, this is not so clear anymore. Given such percentages, it seems clear that whatever form is eventually shown as a default, there should be some sort of footnote that makes it clear that other arrangements of group 3 are commonly encountered.

So textbooks aren't so helpful either. We can get confirmation that the dispute exists, and that we have significant names on both sides, but we still don't have any idea which should be primary.

Specific articles, texts, books, etc. focusing on the issue

We now come to what I feel is the most important argument. Probably most textbooks do not have their focus on this issue, and so it is necessary to look at articles also that do.

Probably one of the most cited articles about this is William B. Jensen's from 1982 supporting Lu. That is the one that even IUPAC referred to above. In fact even La advocates have complained about how often it is cited (e.g. Lavelle). In this article he brings together much supporting evidence from various articles by physicists and chemists. Among those that he cites are:

1. Landau and Lifshitz (1958; yes, seriously, a very noted physics textbook)
2. Hamilton and Jensen (1963), doi:10.1103/PhysRevLett.11.205
3. Hamilton (1965), doi:10.1119/1.1972042
4. Luder (1967), doi:10.1021/ed044p206
5. Merz and Ulmer (1967), doi:10.1016/0375-9601(67)90527-0
6. Chistyakov (1968, two articles that I can't find maybe because they are in Russian)

Another source from this time period (maybe less cited) that additionally support this placement is:

1. Wittig (1973), doi:10.1007/BFb0108579

Today, many articles focusing on the question refer to Jensen (1982) or some of his sources, such as Thyssen and Binnemans (2010) which clearly refers to Jensen (1982), or Labarca and Gonzalez (2019) which clearly refers to Jensen (1982) as well.

As can be seen from the above, this took some time to percolate into chemistry textbooks. Jensen complained in his 1982 article that chemists were at that time generally unaware of the dispute. But now it has been getting quite somewhere. In the 2000s even more articles came in, and a particularly strong voice in favour of lutetium has been Eric Scerri who chairs the IUPAC project mentioned above that is aimed at resolving this question. In recent years his rhetoric has even gone so far as saying that the paradigm of lanthanum in group 3 "must die".

1. Scerri (1991)
2. Scerri (2009)
3. Scerri (2009)
4. Scerri (2009)
5. Scerri (2013)
6. Scerri (2015)
7. Scerri (2019)
8. Scerri (2019)
9. Scerri (2019)
10. Scerri (2019)
11. Scerri (2020)
12. Scerri (2020)

In particular, note his books The Periodic Table: Its Story and Its Significance and The Periodic Table: A Very Short Introduction. Both are popular treatments and both supports the Lu under Y option.

Of course Scerri is not the only source supporting it. We also have quite a few more:

1. Kulsha (1999): available on the author's website, pages 1, 2, 3, 4 (Russian) (author is User:Droog Andrey)
2. Fang et al. (2000), doi:10.1063/1.1322635
3. Horovitz and Sârbu (2005), doi:10.1021/ed082p473
4. Wulfsberg (2006), doi:10.1002/0470862106.ia182
5. Ouyang et al. (2008), doi:10.1063/1.2831506
6. Thyssen and Binnemans (2010)
7. Nelson (2013)
8. Settouti and Aourag (2014), doi:10.1007/s11837-014-1247-x
9. Settouti (2015) (French)
10. Tsimmerman (2018)
11. Labarca and González (2019) (Spanish)
12. Tsimmerman and Boyce (2019)
13. Alvárez (2020)

And what of lanthanum arguments? Well, from before Jensen's 1982 article there is:

1. Trifonov (1970) "Rare-earth elements and their position in the periodic system" – but he lists various arguments, some supporting Lu and some supporting La, and finally picks La on the basis of just one of them
2. Shchukarev (1974) Neorganicheskaya khimiya, Vol. 2

The only ones present in specific articles or sections of books focusing on it, dating from after 1982 when Jensen brought things to chemists' rather than just physicists' attention, are those of Lavelle; Restrepo; and Vernon (= User:Sandbh).

1. Lavelle (2008)
2. Lavelle (2008)
3. Lavelle (2009)
4. Restrepo (2017, doi:10.1021/bk-2017-1263.ch005)
5. Vernon (2020)

Of the last two, I cannot complain; they are legitimate reliable sources supporting Lu. But Lavelle's three articles have all been strongly rebutted by Jensen in his articles of 2008 and 2015. His verdict on Lavelle's La advocacy is particularly devastating:

And he also points out that, contrary to Lavelle's charge that his 1982 article is outdated, the support for Lu in group 3 has significantly increased since he wrote that article, pointing to Ouyang et al. (2008) and Fang et al. (2000).

Although Jensen clearly has a stake in the matter himself as a strong Lu supporter, I feel this should be taken into consideration in some way. Disagreements where one source rebuts another's arguments are of course nothing too special (e.g. Vernon does so to Alvarez), because these are literally opposing views. But the scale of this rebuttal is pretty huge compared to Vernon's rebuttals of a few recent Lu arguments in his paper. So is its tone.

Looking at the fact that La supporters among articles that address the problem in some way are fewer in number, contain one that has gotten a very devastating rebuttal, and the fact that Lu supporters are greater in number and are having a clear effect on what textbooks show (it was slow at first but it's getting somewhere), I submit that the literature-based case is in favour of lutetium as a default. It has the support from most of the articles discussing the issue, and that has already percolated into support by some significant, established textbooks such as Clayden et al.'s Organic Chemistry (hardly fringe), as well as significant, established popular treatments of the periodic table such as Emsley's Nature's Building Blocks and Scerri's The Periodic Table: Its Story and Its Significance. This isn't just a bunch of articles saying B is true and railing against A when textbooks continue to say A in spite of them, like it would have been in the 1990s. It's a bunch of articles saying B is true and railing against A when a significant number of noted textbooks have followed them and have started to say B. And creating an argument that IUPAC has acknowledged. Note that Scerri, Jensen, Lavelle, Restrepo, and Ball are all on the IUPAC project!

That is not to say that we should sweep the whole issue under the rug and pretend that Lu has already won and gotten the IUPAC approval. Of course we shouldn't do that. But it does mean that I think the best way to deal with this situation is to present lutetium in group 3 as the main thing, and to mention in the footnote that lanthanum in group 3 is also a common placement. For a generally used template, this could be done like so as I proposed above.

That nicely reflects the situation: IUPAC hasn't yet made a decision, and the literature is undecided as a whole, but the subset of it focusing on this issue skews towards Lu in group 3. When IUPAC makes a decision, we can revisit depending on what they say and how many chemists listen to them.

Finally, insofar as that is worth something, this layout is exactly that of the 32 column form given in the IUPAC 1990 Red Book (expect that it doesn't have the colours, has the old alternative group numbers also, lacks the note on group 3, and lacks the elements past Lr which had not yet been officially named at the time). Double sharp (talk) 10:15, 18 October 2020 (UTC)

P.S. Ancillary argument brought to my attention by User:YBG

Although my personal inclination is already swayed by the above argument, focusing on the sources focusing on the group 3 question based on my reading of WP:CONTEXTMATTERS, User:YBG gave another argument I agree with in his !vote.

The point of that argument is that Sc-Y-Lu in group 3 is definitely more consistent with the Aufbau principle in that it clearly puts the 4f elements before the 5d elements. That is in the sense of just filling in electrons: so when trying to guess the electron configuration of erbium in the ground state, you see 68 electrons as Z = 68, and fill them in from lowest energy orbital up in the order 1s, 2s, 2p, 3s, ... demanded, and get 4f6s as it correctly is. This is, in general, the sense in which Aufbau is discussed: not about differentiating electrons, but about whether the total ground-state gas-phase configuration matches what happens if you do that. This is why molybdenum 4d5s is universally considered an Aufbau anomaly even though it has the correct 4d differentiating electron from niobium 4d5s, because Aufbau used in the accepted sense would predict it to be 4d5s (which is a little bit up in energy). But technetium 4d5s, the next element, is never considered an Aufbau anomaly even though it has the wrong 5s instead of 4d differentiating electron from molybdenum.

The argument therefore is that since it is pretty universally agreed that the Aufbau principle has something to do with the shape of the periodic table, it is significantly easier to do the sort of explanations typically found in textbooks on periodicity if one uses a Lu table. If one uses a La table, one often ends up with the "pedant's hand raised at the back of the classroom" phenomenon: one has to note that the table does not follow Madelung there, that La is the one transition metal of the third transition series that is not affected by the Ln contraction, and so on. Yes, some sources happily self-contradict (Greenwood and Earnshaw actually does it for the second issue I mentioned), but it's an easily avoidable self-contradiction. That seems to me to be a case where WP:IAR could be reasonably applicable: both La and Lu have some reasonable source-based cases going for them, but it is just easier to write the article without lurking self-contradiction to be swept under the rug if Lu is given first place. Double sharp (talk) 22:32, 6 November 2020 (UTC)

A couple of notes from before

I originally posted this as a discussion thread, but we have discussed this to death already, so I decided to turn it into a !voting thread since no one else has posted !votes / opinions yet. I posted an extremely long rationale for my !vote, but the actual question itself seems pretty neutral to me. Mostly, I just want to get this through, having discussed this topic in various iterations on WP pretty much since the year started.

Some earlier discussion took place and is below. Double sharp (talk) 15:17, 18 October 2020 (UTC)

Finally I note: we have already had a significant amount of support expressed for Lu in group 3 as default here. I have been strongly supporting it in the previous discussions; so has User:Droog Andrey; so has User:ComplexRational; so has User:YBG; so has User:Dreigorich (although he's since retired); so has User:Officer781. Against we have User:R8R and User:Sandbh. Now, on our side, it is true that Droog Andrey has written an article off WP supporting his favoured side, but so has Sandbh. If you subtract those, we still have a very solid majority against a minority of one. Now, it's true that previously when we were doing this the argumentation was more about the science than the sources, and we were not considering a footnote, so we do need to check with everybody (except retired Dreigorich) if the support still holds. But it is indicative I think. Double sharp (talk) 10:27, 18 October 2020 (UTC)

@EdChem: Forgot to ping you, sorry. Double sharp (talk) 10:47, 18 October 2020 (UTC)

@Double sharp: One question, if I may: is the proposal only about the group 3 debate or is it also about moving the primary categorization scheme to blocks only? I had the feeling it was the former but the illustrative table uses new categories, too.--R8R (talk) 10:54, 18 October 2020 (UTC)

@R8R: Sorry, it's just about group 3, and I grabbed the wrong PT. Excuse me while I delete it and make one that sticks to current categories and just moves Sc and Y. Double sharp (talk) 10:58, 18 October 2020 (UTC)

@R8R:  Done Now it shows current categories. Double sharp (talk) 11:01, 18 October 2020 (UTC)

Moved from Opinions to Supplements

Comment by EdChem and ensuing thread

This subsection moved from § Opinions with the permission of its two contributors, EdChem & Double sharp: as noted in § A small question. YBG (talk) 02:23, 21 October 2020 (UTC)

• Comment: I am not comfortable with the wording of the note. The central point, IMO, should not be about the dispute, it should be about the science. I think the note should focus on the fact that La, Ac, Lu, and Lr each have properties that are consistent with grouping them with the inner transition metals or with the transition metals, and that there are reasonable arguments for both classifications. As any element appears only once on the PT, a choice needs to be made as to how to position them. IUPAC have a working group, which has yet to report its recommendation, that will be used to provide an official position. Even once this occurs, however, it will need to be recognised that the properties of these elements will be more typical of the alternative placement. This is obviously too long but I suggest that the feeling of this is more appropriate – that the science supports different interpretations rather than the scientists are having an argument because of (whatever)... when I read the NB this morning, I thought of how we can say that "whether coronavirus is a major health threat or a triviality being scaremongered by evil people who don't agree with individual X (whoever that is) is under dispute in the American community." An imperfect analogy, obviously, but the point is not that there is a dispute but that there is a reasonable basis in science for it. For readers, knowing that the properties of the elements are not always consistent with their position on the PT is valuable information, IMO. EdChem (talk) 21:26, 18 October 2020 (UTC)
  • Aside – A request: Please can we keep !voting to simple support / oppose with reasons? A support is weighted more highly in a consensus discussion because of the quality of the evidence presented or policy rationale, etc... it is not weighted more highly because of the strength with which the view is held. I super-dooper mega-support with a cherry on top that there should be a law against mornings, but that doesn't make it any more likely. Thank you. EdChem (talk) 21:26, 18 October 2020 (UTC)
    • OK, changed to just a plain support by striking out "very strong". ^_^
    • I'm totally OK with changing the note's wording! The only thing I feel strongly about here is that Lu should be the primary option shown and that La should be the one mentioned in a footnote. And even for that, I will bow to whether consensus ends up for it or not. Exactly how the footnote should be worded is something where I agree my current option can be improved. ^_^
    • So far as I can see, the different scientists involved in this disagree on exactly which properties are important for periodic table placement, and exactly how those properties should be interpreted. On the first, you can see the argument about whether electron configuration or chemistry is most important for placement. The second is why you can sometimes see the exact same property being pointed to both by La supporters and Lu supporters as evidence for their position. So maybe that's an OK summary to be added to the note: "The disagreement is based on which properties should have most significance for periodic table placement and how those properties should be interpreted for that purpose", to be added as a middle sentence. Or something like that, I'm writing quickly and it's probably not the best wording, but maybe it will serve as another idea that can be improved on. Hopefully that is not summarising so far that it becomes OR intepretation, though. If you like the improved note, I can add it, although I worry that it may muddy the waters of who is supporting what and whether opposition is against the footnote or against the choice of Lu primary + La footnote.
    • As for what happens after IUPAC makes its decision, I think I would rather look at the situation then. It's possible that they make a decision and everyone accepts it and the other option dies out outside historical texts. It's also possible that they make a decision and a lot of people protest against it and we end up in a situation where IUPAC has made a decision that is vocally disputed and that a significant number of chemists don't follow. And it's also possible for something in between total instant acceptance and instant strong protests. Each of those situations will require us to reflect things differently; the footnote might be able to vanish in the first case, but certainly not in the second. So I prefer to wait and see how the situation evolves after the decision happens and see whether we need a footnote then and if so, what it should say; for now I'd rather focus on the situation now.
    • P.S. I agree totally with your last sentence. ^_^ Double sharp (talk) 22:23, 18 October 2020 (UTC)
    • @EdChem and Droog Andrey: I should remember to ping more often, sorry. Double sharp (talk) 22:26, 18 October 2020 (UTC)
      • @EdChem and Double sharp: Looks like the footnote-text needs discussion, but develop this in a separate thread? Makes it easier to follow the science/encyclopedic discussions here. -DePiep (talk) 16:39, 20 October 2020 (UTC)
        • @DePiep: For sure, it can be discussed in a separate thread how the footnote should read. I would like to keep the separate issues separate too, as it would probably help clarify the flow of discussions. Double sharp (talk) 18:34, 20 October 2020 (UTC)

End of copied thread. YBG (talk) 02:23, 21 October 2020 (UTC)

Details of Sandbh's opinion and ensuing thread

This subsection moved from above (in § Opinions) with the permission of Sandbh as noted in User talk:YBG § Another small question.

Rather, a (politically-charged) project sponsored by IUPAC will deliver a report and make a recommendation. At this point, IUPAC will consider whether or not to provisionally accept the report. If they don’t, the report will die. If they do, the report will presumably go out to at least the chemistry community for feedback. Once the consultation period has closed IUPAC will consider the comments. At that time, they may decide to ignore the report, or start the process of turning it into an IUPAC recommendation.

On sources: Most of those focusing on the group 3 issue, and finding in favour of Sc-Y-Lu, are based on single arguments. This is unscientific. In contrast, Jensen (for example) attempted a multi-argument approach. His work failed to gain traction since, as Scerri, mentioned, Jensen was too selective in his arguments (Scerri & Parsons 2018, p. 143; Scerri 2020, p. 394).

In contrast, the Russian author Trifonov (1970) considered several arguments, and found in favour of La.

There are far fewer sources arguing in favour of Lu simply because La is the accepted standard; effectively no one has been convinced by the Lu arguments; and effectively no one has seen the need to argue for La.

The big three i.e. G&E, C&W, and Wiberg, are unanimous in their depiction of La in group 3.

Scerri's view: Scerri, who is chair of the Group 3 project, concluded that arguments based on physical, chemical and electronic properties are inconclusive (Scerri 2020, p. 381). He acknowledges La is the most common form (Scerri 2020a, p. 10).

On sources (cont.): My article (Vernon 2020, published online 24 Sep) is the first to step back from the minutiae of physical, chemical, and electronic properties and explore considerations of regularity and symmetry, natural kinds, quantum mechanics, and philosophy. It concludes with a series of ten interlocking arguments, supporting La, in the context of a chemistry-based periodic table. This article was subjected to three peer reviews. Scerri is the the journal editor.

Textbooks: Like Double sharp said, Lu has gotten into an appreciable number of textbooks. The IUPAC survey (1970s to 2010s) sampled 193 of these. The count was La 130; *-** 33; Lu 30 i.e. about 4: 1: 1 in favour of La. For Lu, 30 out of 193 is appreciable, and worth mentioning, and nothing to write home about.

More: I'll elaborate in the Supplements section.

--- Sandbh (talk) 01:15, 21 October 2020 (UTC)

End of details of Sandbh's opinion moved from above (in § Opinions). YBG (talk) 01:39, 23 October 2020 (UTC)

This subsection moved from above (in § Opinions) with the permission of its two contributors Sandbh & Double sharp: as noted in User talk:YBG § Another small question. YBG (talk) 01:39, 23 October 2020 (UTC)

I am not convinced by this.

1. While it is true that IUPAC will not necessarily make a decision, there is no denying that it has a project that has the intention of doing so;

   The project has no decision-making power. Rather, it’s recommendation will considered by the relevant IUPAC committee, who will decide (or not) what to do with it, as I explained. Sandbh (talk) 11:21, 22 October 2020 (UTC)

2. There are clearly plans for a IUPAC recommendation, because the project explicitly says "This project will deliver a recommendation in favor of the composition of group 3 of the periodic table as consisting either of the elements Sc, Y, Lu and Lr, or the elements Sc, Y, La and Ac";

   Yes, the project will deliver a recommendation, which may or may not see the light of day and which may or may not be acted upon, along the lines I have explained. Sandbh (talk) 11:21, 22 October 2020 (UTC)

3. Since Sc-Y-* is not one of the two options listed, it stands to reason that there must be some sort of plan to deprecate Sc-Y-* by the project if and when it should succeed in making a decision that gets approved;

   There is no such plan since that would not be within the scope of the project. Sandbh (talk) 11:21, 22 October 2020 (UTC)

4. I have never stated that IUPAC has decided in favour of any form of table. In fact I explicitly stated that it has not. That does not change the fact that it set up a project aiming to give a recommendation on group 3. It seems completely reasonable that this means that there is some intention, in some part of it, to decide in favour of a particular form of group 3 and nothing else.

   There is no such intention. IUPAC does not turn upon the recommendation of a single project. Don’t mistake sponsorship of one project to mean broad IUPAC endorsement, nor an intent, necessarily, to act. I addressed what is more likely to happen from the IUPAC perspective in my article. Sandbh (talk) 11:21, 22 October 2020 (UTC)

5. I don't know of any reliable source that calls the project "politically charged". Given that in contains both Scerri and Jensen (strong Lu advocates) as well as Lavelle and Restrepo (strong La advocates), one would think that its composition (those four, plus Ball and Ohrstrom) was specifically chosen to be as neutral as possible. The closest I am aware of is Scerri's complaint here where he complains:

Yes, no organisation or project likes to air its dirty washing. There is nothing more I can say about Scerri’s complaint. Sandbh (talk) 11:21, 22 October 2020 (UTC)

5. (cont.) Here there is only an analogy being drawn to politics, and he does not explicitly refer to the project that he himself is chairing. One can guess, and perhaps be right, or perhaps be wrong. But that is moot because the source doesn't say it.

6. I don't know of any reliable source that considers "single-argument" sources to be "unscientific". Since the dispute is partly about what properties are significant for periodic table placement, it is a perfectly scientific and respectable opinion that one criterion is enough to decide the matter. In the 1988 IUPAC report that I mentioned as the source of the * compromise, it was stated that according to electronic configurations as well as according to physical and chemical properties the Lu table was the correct one, and they cited some of those single-argument sources for that statement. "According to the electron configurations of the elements, the scandium group consists of the elements Sc, Y, Lu, Lr. This was pointed out as early as 1959 by L.D. Landau (ref. 20) and later by other authors (ref. 13, 14, 20 to 25)." They just didn't recommend it.

   In science there is something called triangulation, or better. Sandbh (talk) 11:21, 22 October 2020 (UTC)

   The 1988 IUPAC paper is a good example of a low quality report that got all the attention that it deserved (basically nothing). I addressed Landau et al. in my article. Sandbh (talk) 11:21, 22 October 2020 (UTC)

7. Moreover, Jensen's paper in fact collects together some of those "single-argument" sources' arguments and cites them (e.g. Merz and Ulmer, Hamilton and Jensen). It seems very strange to suggest that those arguments were "unscientific" when they were first presented separately, but that they suddenly became "scientific" when Jensen decided to republish them together in one paper, with no actual changes to them. This and the previous point show that the reservation that "single-argument" sources are "unscientific" is not necessarily shared by all scientists.

   Jensen has a good go at triangulation plus. A few people noticed his efforts. Sandbh (talk) 11:21, 22 October 2020 (UTC)

8. Finally, while Scerri did indeed think Jensen's arguments were too selective in the work Sandbh mentions, in those very same pieces he comes out in favour of Lu for different reasons; his "don't split the d block" argument and his "Madelung rule" argument. While he has later retracted the latter argument in a personal communication to Sandbh, he has never done so for the first one. Not to mention that personal communications are by definition not verifiable. There is no reason why different proponents of the same format should agree on absolutely everything. Jensen criticises triads, with Scerri uses; Scerri criticises the properties which Jensen uses; but they both are agreed on the Lu table.

   I addressed the split d-block argument in my article. My pers. comm. cite was reviewed by three peers; as the editor, Scerri read it too, pre-publication. And it's still there. Sandbh (talk) 11:21, 22 October 2020 (UTC)

9. Saying that Jensen's work "failed to gain traction", when it has at least 61 citations, when a significant number of textbooks have started showing the Lu form, when popular resource WebElements shows Sc-Y-Lu and explicitly cited Jensen for why, when you can easily find popular-science books in bookstores like Emsley's Nature's Building Blocks and Scerri's The Periodic Table: Its Story and Its Significance which use the Sc-Y-Lu form, and when Lavelle complained that "In fact the Jensen 1982 paper (6) is often considered the one and only reference needed for continued justification of their group 3 (IIIB) d-block placement in the periodic table", seems rather odd.

   A few people notice Jensen. If he would’ve gained traction there’d be no need for an IUPAC project on Group 3. Sandbh (talk) 11:21, 22 October 2020 (UTC)

10. Trifonov is one of many sources, and I mentioned it. It is also from 1970, whereas many of the sources supporting Lu under Y are significantly more recent.

11. Today a sizeable minority of textbook writers have been convinced by the Lu arguments enough to show Lu tables, reaching 23% in the 2000s and 18% in the 2010s (the dip is because of an increase in the * compromise form, which IUPAC shows even though it does not recommend; the percentage of the La form in fact dropped in this time). That's hardly "effectively no one". Counting this as 30 out of 193 lumps together textbooks from the 1970s to the 2010s. This seems inadvisable because the scientific acceptance of the Lu under Y table changed significantly during this period, with many of the papers mentioned being published then. The percentage of La under Y tables changed from 82% in the 1990s to 48% in the 2010s, but if we lump all decades together the prevalence of La gets pushed up by older and less up-to-date sources from the 1970s, 1980s, and 1990s.

    Like I said, the chair of the IUPAC project has said that the La form is the most popular. The Lu form is no more popular than the *-** form. Sandbh (talk) 11:21, 22 October 2020 (UTC)

12. Sandbh makes a reasonable point that the sources would skew towards Lu because La was standard and no one would have felt the need to defend it. But that only applies to the era when La was an "accepted standard", and the current percentage of 48% of textbooks in the 2010s is not exactly an "accepted standard". It is not even a majority. Once enough people started advocating the Lu table, and enough textbooks moved away from it, there did indeed arise a rearguard action trying to support the La table: see p. 135 of The Periodic Table: A Very Short Introduction by Scerri (2019). So we can look at the percentages from 2008 onwards (date of Lavelle's 2008 article) when this had started happening. Out of the sources from 2008 onwards that I collected, adding Jensen's three follow-up papers, we have twenty-four supporting Lu under Y, and only five (Lavelle ×3, Restrepo, Vernon) supporting La under Y. With Lavelle's papers having been given blistering rebuttals by Jensen. (A scientific disagreement is par for the course, but if Jensen goes so far as to claim that Lavelle's commentary "contains a serious distortion of the contents of original article dealing with this subject", that's something quite significant IMHO.) And in the 2010s the La table for the first time lost its textbook majority and the IUPAC project was established. So we see that even when the La proponents do feel that they are under enough threat that they have to defend themselves, they still don't have a majority. In textbooks they lost it, and in articles they are not even close to it.

13. The big three Sandbh mentioned are great textbooks, but not the only ones around. In organic chemistry, Clayden is on that level, and it shows a Lu table. Not to mention that Cotton & Wilkinson, one of those "big three" textbooks, has in the 4th edition a Sc-Y-Lu partial table on p. 7, while at the same time saying that La is in "Transition Group III" in p. 981, which is not exactly consistent.

    This is an inorganic chemistry matter. Clayden’s book on Organic Chemistry effectively means nothing. C&W are up to their 6th 1999 ed. I don’t know what the relevance of their 4th 1980 edition is. Sandbh (talk) 11:21, 22 October 2020 (UTC)

14. It is true that Scerri sees arguments based on physical, chemical and electronic properties as inconclusive. And it is also true that he admits that the La form is the most common one. But it is equally true that Scerri himself has been a fervent supporter of the Lu form since the 1990s and has been writing perhaps more articles in favour of it than anyone else.

    Yes, and he recognises the distinction between his personal views and his views/role as the chair of the IUPAC project. Sandbh (talk) 11:21, 22 October 2020 (UTC)

15. Sandbh's published article is simply one source among many others.

    Not really. As, I said, it is the first to take a philosophical perspective, and one not bogged down in what Eric regards as minutiae. Sandbh (talk) 11:21, 22 October 2020 (UTC)

Therefore I am not convinced by Sandbh's points. In general, I feel that they overestimate the significance of La-supporting sources and underestimate that of Lu-supporting sources, and I feel that in particular Scerri is being read selectively, and a definition of "unscientific" that is far broader than what scientists seem to use is being adopted, in order to do that. In fact, the way only parts of Scerri's articles are referred to, containing his argument that Jensen was being too selective and his admission that La is more common, but the other parts of the same articles where Scerri (and in one case Scerri with Parsons) supports Jensen's Lu stand for his own reasons are ignored, troubles me greatly. Because that means putting only part of Scerri's view under a paragraph headed "Scerri's view", and ignoring the part that is strongly in favour of Sc-Y-Lu that Sandbh is opposing. And hopefully I have kept this statement of disagreement content-based and not personal; if not, I can do some rewording. Double sharp (talk) 09:31, 21 October 2020 (UTC)

@Double sharp: Since I posted on 7 Oct about the ACS Inorganic Chemistry Division, and their return to using a 32-column La logo, that is still their practice. Sandbh (talk) 11:39, 22 October 2020 (UTC)

@Double sharp:. Quick comment. You only know what has been publicity released (≤20%). You know nothing about organisational politics (the 80% under the water, like an iceberg). I know more than I can disclose since, if I did so disclose, my sources would dry up. Even with what you know about what was has been publicly released you are reading things into this that have no demonstrable basis in anything, aside from wishful thinking. I'll see what I can add to my quick comments, a bit later on. Thanks. Sandbh (talk) 06:52, 22 October 2020 (UTC)

@Sandbh: And why should we consider what has not been publicly released when it is by definition not verifiable? Double sharp (talk) 08:35, 22 October 2020 (UTC)

@Double sharp:. Because we are project members who are committed to a common purpose, who bring gifts differing to our collective endeavours, and who hold each other accountable for our successes (or not), rather than citing WP:POLICY. How do you see that? Sandbh (talk) 09:59, 22 October 2020 (UTC)

Let me clarify. I don't see any "wishful thinking" in what I wrote. It seems to either be based on what was written in the reliable sources, or at least a totally reasonable inference from them. The others (@YBG, ComplexRational, DePiep, R8R, Droog Andrey, and EdChem:) may wish to comment on that, though. Based on WP:V, whatever is not publicly disclosed is not something we can reflect because nobody else can verify it. So even in the hypothetical extreme situation that what the website of the IUPAC project has to say about its goals are completely wrong, and the real one is not publicly released, we have to reflect what is publicly said. Double sharp (talk) 08:49, 22 October 2020 (UTC)

End of Double sharp's response and Sandbh's replies moved from above (in § Opinions). YBG (talk) 01:39, 23 October 2020 (UTC)

Discussion on YBG's reasons for supporting Lu

YBG's post, hereunder, as copied from here.

"Support Sc-Y-Lu due to: (1) more pleasing esthetics; (2) greater consistency with the Aufbau principle aka Mandelung rule, a good first-order approximation that gets stressed as orbital energy levels grow closer and then crumbles in the face of relativistic effects; (3) closeness to Janet's Left Step periodic table; (4) Apparent increasing RS support per Double sharp. My opinion is swayed by (1)>(2)>(3)>(4), contrary to WP policies, but there you have it. I will loose no sleep if we keep Sc-Y-La until we know IUPAC's decision and the reaction to it. Let's reach a decision quickly, lest our energy and creativity is redirected away from WP improvements we all agree on. YBG (talk) 05:42, 19 October 2020 (UTC)"

@YBG: If I may rain on your parade ^_^:

1. What did you mean by "contrary to WP policies"?

2. The Lu form is less consistent with Madelung rule, since it has 13 discrepancies compared to the 12 of the La form

3. "Aesthetics" is a culturally dependent criterion and, as such, has no basis in science. Since, many folks seem to be swayed by aesthetics and symmetry, I started a new section about this.

--- thank you, Sandbh (talk) 03:49, 25 October 2020 (UTC)

By "contrary to WP policy", I mean that by my understanding, WP policy does not allow us to make such content decisions based on esthetics (my 1), nor on consistency with Aufbau (my 2) nor Janet (my 3) except to the extent that such esthetics or consistencies are WP:DUEly represented in WP:RSs. I was laying my hand on the table for everyone to see its weakness, acknowledging that my only reason anchored in RS (my 4) was the lowest on my list. Hence, I said, "contrary to WP policies, but there you have it". Perhaps if I had expressed myself more clearly, you might have included your 16K word essay in its own ==section== and simply included a wikilink to it. I think that would actually have strengthened your case (and not just esthetically) . YBG (talk) 09:50, 25 October 2020 (UTC)

R8R's considerations

Luckily, by the time I found enough spare time to write down a response, the most prominent supporters of both versions have spoken up.

Double sharp's position amounts to a few key points:

D1) IUPAC's recommendations are not conclusive;

D2) Textbook usage analysis is not conclusive;

D3) Texts that tackle this particular problem clearly favor -Lu-Lr.

Sandbh's position boils down to the following points:

S1) Most -Lu-Lr apologists have bad arguments;

S2) There are few visible -La-Ac apologists because there is little reason for them to speak up;

S3) Scerri says -La-Ac is the most common form;

S4) -La-Ac has a noticeable majority in textbooks published since 1970.

I do not entirely agree with either line of reasoning.

D1) I agree with Double sharp that IUPAC's recommendations are inconclusive.

D2) I would not be so quick to discard the textbook usage, however. Even the 2010s shows a noticeable plurality for -La-Ac, which beats -Lu-Lr 3 to 1. The 2000s show a majority for -La-Ac, which again beats -Lu-Lr almost 3 to 1. I will consider the data before 2000 outdated and not relevant. Textbook analysis clearly indicates that -La-Ac is the preferred option, even if one can consider this indication not decisive.

D3) I mostly agree with DS. I do have the feeling, however, that this argument in itself very strong. Most of sources presented are research articles, and most argue for a change towards -Lu-Lr. For a tertiary source such as our encyclopedia, it should rather matter that sources that mention group 3 more often than not go for -La-Ac; we shouldn't add momentum to such a change, merely point out what the default version is, and even some of those -Lu-Lr sources admit it's -La-Ac.

S1) That may or may not be true, but that is irrelevant because we are not doing science here and casting our judgment on what Mother Nature is; as a tertiary source, we merely reflect what reliable sources say.

S2) That may or may not be true, but that is equally irrelevant. Either it's in reliable sources or it isn't; the former counts, the latter doesn't.

S3) I agree with this statement and its implications.

S4) I would say that 1970s or 80s are increasingly irrelevant, but I agree with the general point since recent sources (from 2000 onward) still prefer -La-Ac.

Given that we are a tertiary source, a phrase I used a number of times over the last few weeks, I believe the arguments still show there hasn't been a game changer (one may consider a possible future resolution of the IUPAC group 3 project in favor of -Lu-Lr such a game changer), and we should stick to -La-Ac for the time being, as much as I would have personally preferred to pick the other option.--R8R (talk) 15:40, 25 October 2020 (UTC)

@R8R: Thanks for your response; I have noted it, and agree with your characterisation of my line of reasoning. Even though I don't agree, I respect your position and its base on how WP should be a tertiary source. And I also greatly respect how you decided on your choice based on what WP is even though you personally prefer the other option.

Can I clarify with you: would you support a general footnote whenever the precise composition of group 3 appears, even with La as the up-front option? Or would you prefer it the way it is now at {{Compact periodic table}} with no such thing? Personally I think that with no footnote it goes too far and hides the controversy that exists, but I'm ready to hear your source-based opinions. ^_^

Now, I'll just comment based on the source thing.

• I can agree with your characterisation of the textbook situation (D2); La is still more common, just not decisively so. My worry is exactly how relevant this is. Cotton and Wilkinson 4th edition had no qualms both speaking in terms of the La table and also at one point using a Lu table for an illustration. And, well, sometimes you find textbooks showing a La table, but making statements about the result of the Ln contraction that are only true in a Lu table (Greenwood and Earnshaw does this). So I am not sure if this should be weighted so highly: it does seem that outside the people who spend time arguing about it, this issue is not given much weight. But that's probably true of many specialised topics (e.g. is there d orbital participation in SF₆?). And if that's the case, then if I read WP:CONTEXTMATTERS correctly we should focus on the subgroup of sources that actually do care and know about this. That page says Information provided in passing by an otherwise reliable source that is not related to the principal topics of the publication may not be reliable; editors should cite sources focused on the topic at hand where possible. In other words, I think that analysing group 3's composition, as opposed to just mentioning the elements there, should give sources more of a say here. Just like the precedent of how hypervalence clearly says that there isn't d involvement in these molecules like SF₆ even though many textbooks will still tell you there is such a thing.
• The "check and balance" that can prevent this from turning into a helium-in-group-2 situation (which is often advocated among the people looking at that issue, but no one listens to them) is IMHO simply to ask that a significant number of textbooks have agreed and followed this literature – which for Lu in group 3 is a "yes" even if it's not the majority yet, but for He in group 2 is an obvious "no" at this time.
• I take the point that we shouldn't "add momentum" to such a change; we can only follow it. I agree with that. But it seems to me that among the people who analyse the situation the momentum has already led to the change, and I'd argue that those are the ones who matter most. Among people who care about the group 3 thing, Lu is for sure dominating. And among people who don't care about it, few seem to actually be protesting the change (like your response to S2).
• Many of the sources are research articles indeed, but many are not. Well, among the Scerri pieces I linked, there's not only some research articles, but also a Chemistry World podcast, a general-interest book, an Education in Chemistry opinion piece, the Oxford University Press blog, and two popular books: The Periodic Table: A Very Short Introduction and The Periodic Table: Its Story and Its Significance. It seems to me that he's done a lot to bring this issue to the interest of general readers (I recently saw the last of those books in a general bookstore, after all). And in fact the advocacy also appears in such a popular book as John Emsley's Nature's Building Blocks (p. 651, 2011 edition), where he points to Jensen. So I'd argue that it's not only specialised sources that are behind this bandwagon. A general reader who just picks up some texts for laymen has actually a good chance of having heard about this issue now. Yes, that's mostly thanks to Scerri, but he's notable and his books have a wide reach.

Anyway, that's just my view. It's perfectly all right with me if you are not convinced to weight D3 as highly as I'd argue for; the discussion in this section is based on RS, and that's all I ask for.

Regarding "game changers". I just want to ask, what would you consider as a possible game changer? Say, what if in this decade:

1. IUPAC still doesn't make a decision, but La were to dip and Lu were to rise in popularity to the point where they are more or less equal?
2. What if La dipped significantly below Lu in popularity but IUPAC still had not made a decision?
3. What if IUPAC made a decision in favour of Lu, but the proportion of La vs Lu in textbooks remained the same as it is now?
4. And what if IUPAC made a decision in favour of La, but sources in spite of that massively migrated to the Lu form?

I just ask to clarify, of course. ^_^ Double sharp (talk) 16:33, 25 October 2020 (UTC)

@Double sharp: IMO:

1. We go through the same process we did with group 12 as TM or PTM.
2. We go with Lu
3. That's hard. It wouldn't necessarily tip the balance decisively in favour of Lu, but it's certainly a consideration, noting it can take a while for textbooks to catch up. It would also depend on the calibre of the Group 3 report, and the deliberations of the relevant IUPAC committed that result in their acceptance of the report.
4. IUPAC is not necessarily authoritative, given their history of widely ignored recommendations, including some dumb ones scoffed at by Jensen.

Sandbh (talk) 06:25, 29 October 2020 (UTC)

@Double sharp: I think a note about group 3 in the likes of what pl.wiki does will be in order if we don't mention the IUPAC taskforce in it.

My understanding is that a mention in a textbook is a context close enough because element textbooks are concerned with elements, and that WP:CONTEXTMATTERS merely advises against mentions that are not primarily about the topic at hand (in this case, chemical elements) whatsoever. Say, imagine a newspaper note about an airplane that has crashed into the IUPAC headquarters (is there such a thing as the IUPAC HQ?), and damaged was the room where the official group 3 was to be announced the next day, and the newspaper briefly mentions -La-Ac was the more popular form. I take it this is the kind of source one shouldn't use, but a chemistry textbook is fine.

I'm generally not a believer in game changers, but I'll find it acceptable (even though not preferable) if we decide to follow IUPAC no matter what. My preference would be that the IUPAC decision is used to tip the balance in an otherwise near-equal distribution (40:60) and not used as the decisive argument otherwise. I can't think of any other potential game changer.--R8R (talk) 11:54, 1 November 2020 (UTC)

@R8R: I'm OK with not mentioning the IUPAC taskforce. As I've noted, I generally have no strong opinion about exactly what the note says. I feel that there should be one, but that is something I can be persuaded on.

Regarding WP:CONTEXTMATTERS; yes, for sure a textbook is more relevant than a source like the hypothetical one that you describe. However, is it the most relevant? I think that by the same token a source that specifically outright says it's going to focus on the group 3 issue in a section of it is going to be more relevant. A textbook is going to at least partially be concerned, after all, with pedagogy. It may simplify things to make it easier to learn, it may introduce its own nonstandard terminology to make things easier to learn, and it may even be forced to use some theories that are known to be wrong already just because the syllabus it has to follow has not been updated. So it comes back to my quibble about the whole hypervalence thing. If every serious source in the journal literature says there is no d involvement in SF₆, but tons of textbooks still tell you that based on older ideas, then surely the fact that the literature is professing to refute that idea and their focus on it gives them more weight, no?

I mean, this is pretty much what's explained in WP:VNT: For example: George Washington was born in 1732. Let's consider a tour guide who says, "Washington D.C. is the capital of the United States, and it's named after George Washington (1722–1799), the first president ...", then that's just a mistake. But if we have an article written by some famed historian, stating something like "New historical evidence would date the birth of George Washington to 1722, ten years before it was usually known", then it would be a different thing ... regardless of whether such a hypothetical claim was true or not. And indeed, I know an example where something like that actually happened. Consider Johann Mayrhofer (Austrian poet): so many biographers say his birthday was 3 November, but new research (going back to his baptismal record) says it was 22 October, and we show that. Because the source saying 22 October specifically focused on his actual birthdate and provided historical evidence; for his other biographers, it is just one piece of information among many. That seems to me perfectly analogous to what's going on with the Lu vs La issue, except that the case seems even stronger: many textbooks say Lu is an f element, but quite a few are starting to disagree, and the vast majority of the sources that specifically focus on Lu vs La say that Lu is a d element that belongs in group 3 and provide evidence for it. And just like a source focusing on Mayrhofer's birthdate specifically is more reliable than one who is writing a biography of him and therefore has to treat it as just one among many pieces of information that may not have been analysed – a source focusing on the group 3 issue specifically is surely more reliable than one who is writing a whole textbook covering the chemistry of all the elements, for which La and Lu are just two among over a hundred. So it would be like the Mayrhofer thing, except that we'd have a situation where some biographers start to give him the right birthday, which seems to make the case for a change even stronger.

So it's my viewpoint that the most relevant sources are the tons focusing on the issue and saying that Lu should be in group 3. Okay, yes, there are a few dissenters. That's why we can have a footnote: the situation in the most relevant sources is not quite settled but very clearly skewing strongly to Lu. In the next tier of sources, we have the usual lag of textbooks when it comes to this information, but some have already followed. Double sharp (talk) 12:33, 1 November 2020 (UTC)

My understanding that the difference between the Mayrhofer example and the group 3 issue is that the statement "Mayrhofer was born on October 22" is a matter of fact; it can be either true or false. Same with "SF₆ uses d-orbitals": it can be demonstrably true or false. In contrast, "lutetium is a group 3 element" is not; whether this statement is agreed upon or against, it's a convention one way or another. The true-or-false statement here would be, "for each professional secondary source that suggests that group 3 is Sc-Y-Lu-Lr, there are at least two that say it's Sc-Y-La-Ac." Or you can try to come up with a different statement that is either true or false, but it should be clear there is a difference between the Mayrhofer and SF₆ examples on one hand, and the group 3 example on the other.--R8R (talk) 13:14, 1 November 2020 (UTC)

@R8R: Ah, I think we've now gotten to the point where we currently disagree. Is "lutetium is a group 3 element" a convention, or is it a true-or-false statement? I think that, once you define what a "group 3 element" is, then it immediately becomes a statement that you say is true or false, no? And the same thing for statements like "lutetium is a transition metal" or "lutetium is a d block element", all of which amount to the same thing. Once you define the group 3 elements / transition metals / d block elements by properties, independently of the elements, then "lutetium is a group 3 element" becomes not just a convention but something you can prove or disprove according to your definition.

More importantly, it seems to me that the sources in question are treating it as a true-or-false statement. I mean, look at some of the sources: they seem to be pretty clear about what they're saying. Merz and Ulmer says "only lutetium, but not lanthanum, may be considered as a transition metal." Tsimmerman says "This should disqualify them from holding terminal positions in f-block". Fang et al. says "lutetium should occupy the position normally given to lanthanum in the periodic table." And Jensen says "Since such an interpretation is not possible for Lu/Lr, it pretty much determines that this pair should be assigned to the d-block whereas the La/Ac pair should be assigned to the beginning of the f-block." All of these authors seem to be presupposing the idea that there is a sense of correctness and wrongness when it comes to placing elements on the periodic table, because they give criteria that "determines", "disqualifies" placements, to argue why some element "should" occupy this position and not that other one, to argue that we "may" or may not consider something as a transition metal. And it seems that apart from Sandbh who thinks that other forms will continue to have their uses in their contexts, La-Ac supporters seem to have the same idea. Lavelle says "Please leave lanthanum (La) and actinium (Ac) where they belong, in the d-block." That shows the idea that there is some correctness, of places where elements "belong" on the PT. And Restrepo said "therefore La must be the element located at the beginning of the third row of transition metals", with a "must".

So it seems that whether they support La or support Lu, the idea in general among the scientists who care about this is that "lutetium is a group 3 element" is a true-or-false statement, not only a convention. The disagreement is just on whether it is true or not. So that's why I think the situation is more like the Mayrhofer and SF₆ ones. But what do you think of this argument? Double sharp (talk) 14:25, 1 November 2020 (UTC)

@Double sharp: I understand what you mean, but it appears to me there is something you're missing here. Each individual scientist may think they have the definition of a block, and that's fine. The thing is, it is not necessarily the case that they all think of the same definition, and that's where the problem lies. You may recall Scerri as the chairman of the IUPAC group 3 taskforce also sought to use the definition of a block, but he couldn't come up with it. This is a very good sign the problem is not at all that easy. That's where conventions come in: people have to agree to use the same definition of what a block is, and if that were feasible, that definition would've likely already appeared and been recognized as such. (Lavelle and Scerri think differently on the same issue; does that really seem like this is not where conventions should come in?) In contrast to that, there is not going to be a misunderstanding about the meaning of the statement "Mayrhofer was born," and there is no sense that the meaning of that statement was ever agreed upon rather than arose naturally.--R8R (talk) 12:00, 4 November 2020 (UTC)

@R8R: I see what you mean too, but isn't that just about the arguments they use? Yes, some people argue on block-based grounds, and they have different ideas of a block in mind. But the statement at hand is not "what is a block", it's "is Lu a group 3 element". The meaning of the statement "Lu is a group 3 element and La is not" is clear, it means "Lu and not La belongs in the same column of the periodic table as Sc and Y". I'd think from those quotes I gave that if you asked a bunch of La and Lu supporters about that statement, they would agree what it meant, and they would agree that it was either true or false. (Of course they wouldn't agree on which of it it is, but there would be agreement that it is a fundamentally decidable proposition.) It's the way you get there where the individual conventions live, like "what is a block", like "what criteria should be used to decide PT placement"; but those are just justifications, and don't impact the clarity of the statement at hand and its nature as something that can be either proved or disproved. Obviously, if scientists find themselves at different conclusions, they must be justifying their conclusions in different ways. In fact, some scientists who find themselves at the same conclusion are justifying it in different ways (Jensen vs Scerri, for example). So people disagree on how they get there, people disagree on what the truth of a statement is, but they agree that it is either true or false. That does not seem different from any other disagreement to me, honestly. And that's why I feel it should be treated the same way: authors differ in methodologies, but they agree the statement at hand is either true or false, and a strong majority says it's true. So we reflect that and just say that there's some opposition, giving it its due weight. Or maybe I misunderstood you? Double sharp (talk) 12:22, 4 November 2020 (UTC)

@Double sharp: Hmm. I think you effectively said the opposite not too long ago? "But the statement at hand is not "what is a block", it's "is Lu a group 3 element" is nice, but I take it it contradicts the notion of "Is "lutetium is a group 3 element" a convention, or is it a true-or-false statement? And the same thing for statements like "lutetium is a transition metal" or "lutetium is a d block element", all of which amount to the same thing." So is it the same or is it not?

"The meaning of the statement "Lu is a group 3 element and La is not" is clear, it means "Lu and not La belongs in the same column of the periodic table as Sc and Y" -- I take it the two statements mean precisely the same. There is no explanation added by any of these statements to the other as far as I can see. I also take it there is no controversy about the statement "a group 3 element is a d-block element." This means if Lu is a d-block element, it's also a group 3 element (because nobody suggests a different position in the d-block for Lu), and if it's a group 3 element, it's also a d-block element. The same goes for La.

However, let's summarize it this way. What is exactly a group 3 element? What's the definition that's clear to everyone and that's going to unambiguously answer that question? If there were such an ultimate definition, then it is without a doubt that a vast majority of reliable source would accept it and what results it produced, right? Well, there is no such definition and there are no such results, which means there is no ultimate answer (but there is an answer to the question "what does it mean when we say a person is born?"). Being in the same column is not an answer; it's the same statement but in different words. The answer could be about electronic configurations, but Scerri rejects such an answer. It's not that easy to give a straightforward answer, which is where conventions come in.--R8R (talk) 13:07, 4 November 2020 (UTC)

@R8R: Well, maybe I'm not explaining myself perfectly well. ^_^ I agree "lutetium is a group 3 element" = "lutetium is a transition metal" = "lutetium is a d block element" as statements, because they lead to exactly the same picture in terms of the PT, like you say in the second paragraph: the one I've been advocating we change back to with Sc and Y over Lu. What I don't think is the same is the question "what is a block". No, there isn't such a thing as the definition that's clear to everyone of what brings an element to the d block, but that's not exactly the statement at play. Because there's general agreement that there is such a thing as a correct placement of elements in the PT; what's not agreed is how to get at it. Even with blocks, there's a general total agreement on exactly how many they are, what they're called, and apart from the group 3 dispute even exactly which elements go in which, after all. So I'd say that the analogue to the question "what does it mean when we say a person is born" here is "what does it mean when we say some element belongs somewhere in the PT". Yes, there's no formal definition, but does it matter that much when apart from group 3 everyone seems to know what elements go in what block anyway?

And, the analogue to the questions like "what is a group 3 element" or "what is a block", which are rather really more like "what criteria put an element in group 3" or "what criteria put an element in the d block" (because "group 3" and "block" seem to be de facto understood even if no formal definitions are agreed on), are rather things about how to find out the information about when someone was born: the birth certificate if it survives, maybe earlier the historical records, maybe the baptismal list, recollections of relatives interviewed afterwards, and so on. Both are about what things should be used to decide a question that is widely understood. (It's not an exact analogy obviously because the real world is more complicated. If you prefer, I can go for a more chemical analogy to be more exact, but it'd be less colourful. ^_^) Historians can debate on which of these sources are more reliable for determining a person's date of birth, but they agree that there's in principle a right answer even if in some cases maybe we can't find it out. Likewise, chemists can debate on exactly what criteria are the most reliable for determining where an element belongs in the periodic table, but by and large they seem to agree that there's in principle a right place for it. So I think the right question is "where is Lu correctly placed in the periodic table = is Lu in the group with Sc and Y = is Lu a group 3 element = is Lu a d block element = is Lu a transition metal", and the definitions are more akin to the debate about how to find out that correct placement. In other words, the question to be answered is "where does Lu belong in the periodic table", and that is not subjective and not subject to convention and is clearly understood; what is debated is "what definitions and criteria are relevant to decide on where Lu belongs in the periodic table", but that's a secondary-level thing. So something like this:

Well, what do you think? Double sharp (talk) 15:18, 4 November 2020 (UTC)

@Double sharp: I agree that "lutetium is a d block element" is not the same as "what is a block." No question about it. However, it seems to me it is rather obvious that you need to answer the latter question before you can formally agree or disagree with the former. (Even in the famous statement "I think, therefore I am," you need to understand what, for example, the words "think" and "am" mean before you can informedly agree or disagree with it. "You were clearly not thinking when you said that" -- does it mean that the person didn't exist at that moment, too, or that the original statement is therefore wrong? Or are there nuances?)

"there's general agreement that there is such a thing as a correct placement of elements in the PT" -- I don't think that's the case. For example, Scerri suggested a table in which Lr is located under La, and after providing his rationale he said that there was no universal PT, and that the elements are not necessarily tied to a rectangular grid in the likes of our PT. Sandbh has also said something like this a number of times this year, too, and I agree with him.

The difference is that birth is a real thing, or at least my common sense is that it's common to treat it as such. In contrast, the periodic table pictures relationships between elements, emphasizing some over others, and relationships are not a real thing pretty much however you look at it, that's something we like to think of. If you look at it this way, I hope it will be easier to see why your analogy does not seem convincing to me. In both cases, the second question is of the nature that resembles "upon the basis of what convention do we agree Lu should be in this place in the PT/the person is registered as born?" Both of these questions represent conventions. One could, of course, reduce any word to a convention that it means something, but it's useful to take something for granted. And birth seems like a very basic thing and people more or less agree it's a thing, not a convention. I'd say that suggesting the same treatment for emphasizing some relationships between elements (an entirely nade-up concept to begin with) over others as a thing and not a convention is a bit too much. Scerri doesn't do this. A Soviet source I've read refers to such a thing as "blurring of periodicity" with respect to the 5d and 6d positions in the PT. I propose that we shouldn't claim there is an ultimate answer, either.--R8R (talk) 14:28, 8 November 2020 (UTC)

@Sandbh: Well, your last paragraph is where I disagree. People are treating this as a thing, rather than as a convention. They must be, or else they wouldn't use the language they do. As shown from my quotes: they say something determines the placement, that something must be put here, that a form is a mistake, that a form must die, that a placement is disqualified, that one may not classify an element this way. Such rhetoric presupposes a mode of thinking that this is not a convention but a thing. Since that is how most sources talk, in my opinion we have to follow it. That's just because of the RS situation. Scerri did not suggest a La-Lr table (that was Poliakoff AFAIK), and in fact he not too long ago did indeed say there was such a thing as an optimal PT. The sources may argue about how you get to the conclusion that some PT is better, and which one it is. But that one is better when it comes to the group 3 problem, they don't argue. Double sharp (talk) 14:42, 8 November 2020 (UTC)

@Double sharp: I'd say that the context, in which those phrases were said, helps establish that these phrases do not imply there is the one ultimate way. For example, in the article in which Scerri says that -La-Ac "must die," he also says, "There is a different reason why placing lutetium and lawrencium, rather than lanthanum and actinium, in group 3 is the better option" (emphasis added), so I would not overestimate the importance of those out-of-context phrases. But if you don't see it that way, I guess it's best to accept that we differ on that. But just to be clear, "optimal" is not "right" or "ultimate," and something can only be optimal if you agree for what it should be optimal, explicitly or implicitly (and that's where conventions come in).--R8R (talk) 15:16, 8 November 2020 (UTC)

@Double sharp: Was that ping for me or R8R?? Sandbh (talk) 05:10, 9 November 2020 (UTC)

@Sandbh: Sorry, it was a typo on my part and meant for User:R8R. Double sharp (talk) 10:31, 9 November 2020 (UTC)

Other discussion

@Droog Andrey: I'd like to read your article about the group 3 issue. The images linked by User:Double sharp (thank you!) are too low quality to enable a translation into English. Is there anything that could be done about this? Sandbh (talk) 21:29, 19 October 2020 (UTC)

@EdChem: There is no fundamental requirement for any element to appear only once on the PT. An appreciable number of periodic tables do not observe this "non-requirement". Sandbh (talk) 22:50, 20 October 2020 (UTC)

Aesthetics and symmetry

Introduction

​​​​​​ As promised, here is a discussion on the (non-)relevance of aesthetics and regularity in the context of the Group 3 question. It is taken and adapted from my peer-reviewed open access article which now has 400 accesses, in Foundations of Chemistry. The editor is Eric Scerri, who is also the chair of the IUAPC Group 3 project.

I caution readers to not confuse Eric's personal view on the group 3 question with his role as the editor of FoC, nor with his role as the chair of the IUPAC project.

My conclusion is that, akin to a game of whack-a-mole, attempts to improve regularity in the appearance of the periodic table increases the number of irregularities amongst various other properties and relationships across the table, and cognitive dissonance with respect to chemical relationships between or within groups or series of elements. Further, while Nature does not care about aesthetics, the composition of Group 3 as Sc–Y–La–Ac appears to be more consistent with the texture of the world.

Scerri sets the scene

Scerri (2008, p. 57) has argued for lutetium under yttrium (and helium over beryllium), since the periodic table can then be arranged, from a philosophical point of view, so that it shows the greatest degree of regularity and symmetry. Such a table may better reflect the regularity of the periodic law. He cites as an example, the left-step or Janet periodic table (Fig. 9). Such a table facilitates a regular array of vertical triads (Fig. 10), in which the middle element of the triad has an atomic number that is the average of those of the first and third elements. Scerri does not support lanthanum under yttrium since, in a 32-column table, and on the basis of regularity and symmetry, this once again results in awkward split d-block (Fig. 11).

Scerri's argument remains inconclusive

His argument remains inconclusive as there is no basis to regard regularity or symmetry as fundamental requirements (Scerri 2004, p. 149; 2019, p. 385). Stewart (2018b, p. 75) observed that, “Triads are a consequence of the structure of the system and cannot at the same time be its cause.” Scerri (2020a, pp. 387, 401) acknowledges that we should be aware of arguments based on regularity or symmetry. Jensen (2019), whose 1982 article in the Journal of Chemical Education kicked off the debate on the composition of Group 3, recently attacked the relevance of triads.

Curiously, as discussed later in this article, increasing regularity in the shape of the periodic table increases the number of irregularities amongst various other properties and relationships across the table. Indeed, as Imyanitov (2016, pp. 153–154) observed: If one seeks for the maximum chemical utility… should opt for the more ‘unruly’ tables. If one seeks maximum elegance and orderliness above all… should favor the more regular representations.

.

The historical obsession with symmetry

The obsession of the Greeks with the concept of symmetry retarded progress in astronomy for at least 1500 years (Yang 1996, p. 271). They perpetuated the idea of the Harmony of the Spheres and the Dogma of the Circles. According to these works, the heavenly bodies must observe the most symmetrical rules, and the circle and the sphere are the most symmetrical forms. But the heavenly bodies do not make simple circular motions. So they tried to fit their motions with circular ones superposed on circular ones. When that did not work either, they tried circular ones on circular ones on circular ones, and so on.

My shock and realisation

The first time I saw a 32-column table with a split d-block (Fig. 11) I thought it must have been “wrong” since it appeared so awkward; I later came to realise that I’d subconsciously adopted the Western cultural obsession with symmetry. Jensen earlier referred to the abuse of (Platonic) symmetry considerations in the construction and interpretation of periodic tables in general, including to the extent of triumphing over the inconvenient facts of chemistry (Jensen 1986, passim; 2003, pp. 953–954).

Symmetry breaking

An emerging field of thought is the importance of symmetry breaking, rather than pure symmetry:

…symmetries matter, largely because we like to see them broken sometimes: the laws, particles and forces of physics all have their roots in symmetry-breaking. They create what David Gross of the Kavli Institute for Theoretical Physics at the University of California, Santa Barbara, calls the “texture of the world”. These considerations have led Florian Goertz at the Max Planck Institute for Particle and Astroparticle Physics in Heidelberg to propose the existence of a new particle that is single-handedly capable of cleaning up five of the stickiest problems in physics. “Complete symmetry is boring,” says Goertz. “If symmetry is slightly broken, interesting things can happen.” (Brooks 2018, p. 30)

As Eugen Schwarz (2019, pers. comm., 8 Dec) stated, "The real, rich pattern of elements’ chemistry does not fit into a clear-cut rectangular grid." This view is consistent with that of Dias (2004, p. 375), who asserted that:

"A periodic table is defined as a partially ordered  set forming a two-dimensional array which complies with the triad principle where any central element has some metric property that is the arithmetic mean of two flanking member elements."

Real chemists

In this vein, Mendeleev used horizontal triads when he predicted the properties of the then undiscovered elements scandium, gallium, and germanium. He discussed his technique using the horizontal triad arsenic-selenium-bromine to estimate the atomic weight of selenium (Scerri 2008, pp. 585–589).

A high degree of orderliness, and explanatory power, can nevertheless be found in Rossotti’s (1998) split d-block periodic table template (Fig. 12).

Rossotti shows where each subshell starts; how the lanthanoids and actinoids are interpositioned between Groups 2 and 4 and, in this instance, the electron configuration make-up of gadolinium and its predecessor, europium. Here, the lanthanoids run from cerium to lutetium; and the actinoids from thorium to lawrencium.

The split d-block is thus integrated into the overall design of the table.

The domain of chemistry

A related consideration is that the internal structure and external shape of a chemical periodic table is determined by chemical facts rather than considerations of regularity, beauty or symmetry (Cao et al. 2019, p. 26, passim). Here, the use of multiple considerations to triangulate a solution is consistent with the role of classification science, as well as the premise that “Classes are usually defined by more than two attributes…” (Jones 2010, p. 169). In other words, in the absence of a categorical solution we are obliged to use quantitative or qualitative arguments to establish a solution.

Conclusion

It is ironic that, akin to a game of whack-a-mole, attempts to improve regularity in the appearance of the periodic table increases the number of irregularities amongst various other properties and relationships across the table, and cognitive dissonance with respect to chemical relationships between or within groups or series of elements. While Nature does not care about aesthetics, the composition of Group 3 as Sc–Y–La–Ac appears to be more consistent with the texture of the world.

That said, since periodic tables or systems form a continuum-like series of representations, different approaches to the Group 3 question (even that used within the IUAPC) will continue to have their uses. And please remember to explain the relevant context to your students.
--- Sandbh (talk) 05:21, 25 October 2020 (UTC)

New periodic table: implementation

I have a proposal about what we're going to do once we've established what changes, if any, we want to see in our future periodic table. So far this includes the group 3 question and the question about categories. I'd like us to implement those changes, if they are approved, simultaneously, and on top of that, there is one more pending change which we could also implement at the same time.

We have established that the current color scheme has potential for improvement. I propose to change the coloring scheme once we have figured out what categories it should have and what their composition would be.

As soon as we have agreed what categories the periodic table should have and what their composition would be, we should not change the periodic table instantly. Instead, we note that a conclusion has been reached and we start a sufficiently long period of time, say, two months, in which all editors who would like to propose a new coloring scheme for the periodic table can craft one. When the period ends, we discuss the submitted schemes and choose the best coloring option. Once we have chosen the next coloring scheme, all changes we have agreed upon go live.

I submit this idea to the project and I would like to hear what other editors think.

@Double sharp, Sandbh, DePiep, YBG, ComplexRational, and Droog Andrey: comments are welcome. Sorry if I forgot anyone.--R8R (talk) 14:46, 18 October 2020 (UTC)

@R8R: I'm not sure I understand you correctly. Do you mean that even after the group 3 and category things are decided, we should wait to decide on the colouring scheme? Personally I think that once we have a consensus on the group 3 options and categories we should let them go live first and then think about changing the colours. Otherwise it gets into the situation again where we have a strong consensus on the Project but things never get anywhere. I found myself, in fact, very frustrated by that situation when we reached the point in the earlier group 3 discussion that we had a massive swing towards changing back to Sc-Y-Lu, but IIRC you told me that we needed an WP:RFC despite that massive consensus here because the previous time it was decided in an RFC. Personally I think that we should be able to solve this as a project because these articles are of interest first and foremost to us among editors; the biggest participants at that RFC were from this project. Changing the colouring scheme requires no less discussion than changing the group 3 thing, so why should one need an RFC and the other not? I found it myself somewhat muzzling along the lines of "we have a consensus, why can't we implement it"? Now I think it was correct in hindsight because that consensus was not so policy-based (it was more about the science argument than the sources one), but if we get the same level of support again, I see no reason why we could not just change it and act on our consensus.

In fact, if the group 3 thing gets a consensus before categories, I would support making the group 3 change live before talking about categories to keep us discussing one option at a time.

So I'd rather put it in the following order: put the questions like this:

1. Do each of us support / oppose the change back to Sc-Y-Lu? (Binary choice. Whatever is decided, the other option must be footnoted, I think.)
   • If Q1 passes, implement general change back to Sc-Y-Lu with the footnotes; if it fails, just add the footnotes to our current Sc-Y-La arrangement. Then pass to Q2.
2. Do each of us support / oppose wiping out the category colouring in favour of blocks only? (Binary choice.)
   • If Q2 passes, implement and finish (we have previously discussed the block colours and I don't think there's anything else that needs to be argued about it). If Q2 fails, proceed to Q3.
3. What changes if any should be made to the current category set?
   • If any change gets a consensus, implement it and proceed to Q4. If not, retain status quo and proceed to Q4. Some sort of time limit should probably be present to prevent things from getting out of hand, like you suggest for the colourings.
4. What colour changes if any should be made now that the category set is decided?
   • If any change gets a consensus, implement it and finish. If not, retain status quo and finish.

I think the bold "implements" are necessary to make sure that once a consensus is reached, it gets acted upon. But what do you think? Double sharp (talk) 15:00, 18 October 2020 (UTC)

I converted my immediately prior thread to become the consensus-gauging thread for Q1. So you and everyone else can !vote there. I kept the question neutral, I left my opinion to my !vote. Hopefully to remain open until all major participants of this project and this discussion have !voted. Double sharp (talk) 15:23, 18 October 2020 (UTC)

What I mean first and foremost is that we should agree on the categories and we use and that we should use the opportunity to change the colors since I recall there is an agreement the color scheme we have today is not the best scheme we could have. So when we roll out a new category set for the public to see, it would be great to introduce new color at the same time.

Many outside people watch our articles from time to time (I used to be a person like that before I joined, for instance) and it seems to me that it would be wiser not to have them see so many consecutive changes, but rather lay them all down at once. That is why it seems to me it'd be a good idea to implement all changes at the same time. In principle, the group 3 question could be decoupled from rediscussion of categories and recoloring them but I feel we could do a better by not doing that. This is, of course, up for debate.

The concern that things can end up not done is understandable. The way I propose to address it is to enforce a strong time limitation. Two months seems like a plenty of time if you want to submit anything. Whatever is submitted in those two months is what we choose from and there's that. If there is a preferable option, it should be obvious to anyone. If there is no agreement on what the preferred option is, we could do anything. We could find an uninvolved editor and ask for their opinion as a tiebreaker. It's going to take a little time but the fear of having the project stumble otherwise should be a stimulus enough for us to solve it collegially.

I also feel that the current coloring scheme has outlasted its welcome, so to speak, and the process I propose seems to be the strongest guaranty that we actually abandon it in the end. So any move from it is likely a good move, and the desire not to be the one to take the blame for not moving is, I believe, a good stimulus to get anywhere. However, we could, for instance, use EdChem's help if we don't manage to sort it out ourselves. We could even end up tossing a coin if we're stuck as far as I am concerned.--R8R (talk) 15:32, 18 October 2020 (UTC)

P.S. I am thinking about your group 3 proposal, not just ignoring it. I'll write something in a few days.

@R8R: Please, take your time. As long as it looks like something is going forward, I'm happy. I just want to see a process, among us project members, actually get to completion and result in a decision based on the consensus or lack thereof. And that's why I'm generally in favour of keeping each thing separate so that different issues are not conflated. If outsiders see things changing slowly, then, well, it's not much different from seeing entire articles change slowly when we rewrite them. ^_^ Double sharp (talk) 15:44, 18 October 2020 (UTC)

• @R8R: (ec) (I like the current ping-all habit, since there are many long threads, evolving, to follow).

re "one more pending change which we could also implement at the same time". I don't think a 'while we are at it, let's change it-2 too' is useful. Instead, I am fine with: once a conclusion is explicitly reached, we can consistently roll it out however much and complicated edits are needed. Meanwhile, any other change can be fleshed out and reach a sound conclusion at its own time. Implementations are not simplified by mixing them -- and isn't that true for discussion equally? I want to call: first of all keep separate topics separated. "Separate" as in: scientifically and logically not connected. (For example: redesign & rewriting Periodic table#Overview can be kept separate from current Group 3 issues).

re improving the category colors (is not categorisation itself we understand): yes after the cat scheme has concluded, that is a challenge to solve (the advantage being: when the number of categories reduces, the requirements re accessability and legend-requirements from-legend-to-chart-or-back can more easily be met; with 7 or 8 or 9 colors this is a huge issue!).

However, your 'period of proposals' setup I don't think effective. First I'd like to establish the requirements: wrt accessability like contrasts and wrt legend like 'can one find the graph color in the legend?, and v.v.?'. (preliminary, for example, I think of getting rid of legend fontcolors because that adds reduces contrast options, so only use black and wl-blue text). -DePiep (talk) 15:33, 18 October 2020 (UTC)

Having read the Double sharp reply (after ec), I think can I agree in this detail. I seriously think we should not tie ourselves to voluntary deadlines. Current colorscheme can serve a new cat-scheme. -DePiep (talk) 15:38, 18 October 2020 (UTC)

@DePiep: I understand about the deadlines. I am willing to compromise and not have them. But I seriously, at this point, want something to get done. I want a process among project members to get to completion and result in a decision based on the consensus or lack thereof. Whatever can make this goal happen gets my support. Whatever the decision is, I want some sort of resolution. A consensus and a decision to implement it. Or no consensus and a decision to do nothing and wait for another year or two. If separate topics being kept separate helps that, which I think it does – then it has my support. ^_^ Double sharp (talk) 15:44, 18 October 2020 (UTC)

@R8R: I understand, including impatience creeping into this. I myself am unhappy all along with the grey and the brown, and the unevenness. Core of my approach would be: let's talk to agree about the requirements first (like contrast, other colors used, and good legend design). Could start right now btw, were it not for other time consuming talks here.

If we do not look critically at the requirements, we are sure to end up with bleak colors: good re contrast, bad re legend functioning. That is: an illustration, not a clarification. Enlarging degrees of freedom is crucial IMO. -DePiep (talk) 16:03, 18 October 2020 (UTC)

DePiep, you see, the last time we discussed a change to a coloring scheme in 2016, a proposal had enough support. We took our time then to see if we could craft a better version and four years after that, we still use the old scheme. That's why this time, I am calling for a time limit. I think there is no real problem if we implement one scheme and then, one month later, we come up with a better scheme. Making two changes is better than making zero changes awaiting for the perfect first one.

If two months is not enough, it can be three months or four months. That is negotiable. The point is, if it is four months, it is four months, because otherwise it risks to be four years and counting just like it is today. We should learn from our mistakes.

To be clear: whether or not we should feature alkali metals is not a scientific decision. It's an editorial decision.

Any timing for recoloring should start only when there is an established agreement on what a new table should display. That much is clear and I hoped I made that abundantly clear in my starting message. I don't expect there to be any precise coloring requirements like contrasts, though I believe, that whether or not there should be new borders or color for states of matter will be a part of it. I asked the project to abandon the state of matter colors a while ago but it was decided they should be kept. Again, everything is up for discussion.

We can, in fact, discuss the requirements right now, so that we're all set when we have decided what categories we should use.--R8R (talk) 16:09, 18 October 2020 (UTC)

@R8R: I agree that we can discuss requirements right now, but also think that we should also leave off more than general principles to when we decide what categories we use. Current scheme, tweaked current scheme, blocks alone, or whatever. Let's decide everything individually to keep things clear. ^_^ Double sharp (talk) 16:19, 18 October 2020 (UTC)

Sad to read that a 2016 discussion is causing distress now. To be clear: "2016" was not derailed or frustrated, it just did not work out well, because it was not viable. Not because I checked it but because from the same reasoning I can redo from memory: 2016 resulted in very flaw bleak colors that did not serve good-legend requirements. Full stop. -DePiep (talk) 21:50, 18 October 2020 (UTC)

The problem here is not the fact we have not adopted the 2016 colors. I think that however you look at it, the 2016 colors were better than what we had back then and what we have now, but it could very well be that even better colors could emerge. The problem is that there was a discussion that even better colors could be made, but we never saw them. I remember having high expectations myself but they were never met; there never was even a presented attempt that could try to meet them. That is the problem that I am aiming to solve.

Of course, the idea of a time limit is a double-edge sword, and it could even backfire if I fail to meet the deadline. If I fail to meet it, there's nobody to blame for that but myself. Fully cognizant of such a possibility, I still believe that a time limit is the way forward. Everybody has the same starting position.--R8R (talk) 17:30, 19 October 2020 (UTC)

(outdent) I agree with this plan of #Progressive implementation. I note (1) I think the ELEM editors would be encouraged and energized by seeing our completed work go live. (2) IMO, this overrides concerns re successive waves of changes impacting those who copy us. (3) It may be helpful to take a day or two to list changes needed before making them, especially in template space. (4) This system generally follows the principles of separation of concerns. (5) We should start a discussion of color selection principles long before we need them. YBG (talk) 06:28, 19 October 2020 (UTC)

@YBG: Thank you! Double sharp (talk) 10:53, 19 October 2020 (UTC)

Since there has been some discussion on the exact form of the footnote, we may add a Q11⁄2 between Q1 and Q2 regarding how the footnote should read. Double sharp (talk) 20:01, 21 October 2020 (UTC)

Coloring principles

Here are the requirements that I can discern; everyone is welcome to add more ideas.

Bare minimum

The following principles must be fulfilled for a legitimate attempt to recolor the periodic table:

• Each category has a separate color that is not used for anything else;
• There are five text colors: black, unclicked wikilink, clicked wikilink, liquid, gas. Of these, only the last two are variable. The five colors must be sufficiently different from one another to allow to tell them apart easily.

More conditions

The following conditions do not constitute a barrier for proposed scheme, but it is nonetheless highly desirable to fulfill them:

• Each pair of a category color and a font color used in the periodic table should have a contrast greater than or equal to 4.5;
• Different types of borders should have colors that are easy to tell apart from both one another and the category colors used for cells that use this type of border.
• Different category colors should be easy to tell apart for users with protanopia, deuteranopia, or tritanopia, and all pairs of a font color and a background color that can be found in the periodic table should be easy to tell apart.

Discussion

The only idea that I am not certain about is whether we want to have colors for predicted elements or not. We currently don't use them, but we might want to rethink on that.--R8R (talk) 17:30, 19 October 2020 (UTC)

@R8R: Let's maybe think about that last one once we've gotten to the phase of discussing whether or not we should have colour categories in the first place – because if anything my concerns about WP:OR apply even more strongly to predicted elements. Other than that, seems quite reasonable to me. ^_^ Double sharp (talk) 17:39, 19 October 2020 (UTC)

@Double sharp: once we've gotten to the phase of discussing whether or not we should have colour categories in the first place – sorry in advance if I missed something obvious (I haven't had time to read the whole thread), but I don't understand this: why would we not have color categories? I understand the logic behind perhaps not having predicted colors, but almost every PT I've seen has color categories. If I missed this, would you kindly point me to it or offer a condensed version?

@R8R: Should we follow the same principles we discussed during an email thread pertaining to the color scheme of the SHE decay modes chart—namely attention to contrast of adjacent categories and colorblind-friendly combinations? In that case, we also should be careful about how many font colors we introduce, but specifics can come later. ComplexRational (talk) 21:01, 19 October 2020 (UTC)

@ComplexRational: I have a draft proposal ready to explain just why I don't think it's wise to have colour categories, but I wanted to keep the issues discussed one at a time, so I have not posted it yet. The brief reason is that although it is common for sources to give categories, the literature has no agreement on (1) what categories to use, (2) what names to use for those categories, and (3) what elements are included in each category. In other words: many PTs have colour categories (not all though, see Greenwood and Earnshaw), but exactly how they divide the elements into which colour categories is not something you will find any agreement on. That is why I am of the view that we are implicitly taking a side by colouring everything in as if it was all agreed and that that is against WP:NPOV and more specifically WP:DUE. And that is why I have been advocating scrapping the colouring of categories in favour of discussing element categorisation in article text, and colouring only blocks, because (1) that's not unknown in the literature as many Russian tables do it, and (2) that is something that apart from the group 3 issue people actually agree on. You can find disagreement in the literature about whether arsenic (or quite a few others in the p block really) is a metal, nonmetal, or metalloid, but you will find no disagreement that it is a p block element. But the full proposal and rationale will wait a bit I think to not muddle issues. It will appear once everyone has commented on the La vs Lu default issue and we put into action the result. Double sharp (talk) 21:12, 19 October 2020 (UTC)

@Double sharp, ComplexRational, and R8R: I think we can go full steam ahead here without regard to the result of any other discussion. Even in the most radical change envisioned, we would still have color categories, although there would only be four of them: s, p, d, and f. We should still apply the same color principles in that case. YBG (talk) 02:58, 20 October 2020 (UTC)

@Complex Rational: sorry for a late response. More or less, yes. This one is going to be more complicated, however, because there are more color combinations to consider. If you want me to, I could describe it to you later in greater detail, at least what I see. There shouldn't be considerations like "this category should be green," but for example, one thing that is rather obvious is that there is a number of gaseous elements in the top-right corner of the table, and the color of those categories shouldn't look too much like the color of the gas font color. Solid elements are present across the whole table, so it's no wonder the color for solid is likely to be black (not reddish, greenish, or blueish).--R8R (talk) 11:26, 4 November 2020 (UTC)

@Double sharp, ComplexRational, R8R, and YBG: re we could run ahead, save for time reasons right away. And save for: this is not a one-dimensional problem. A redesign should have a strong base (including science communication and webdesign, not strongly available in us, habituals). Also, other discussions on this page these months take loads of time to follow, evolve and to disentangle.

For starters, we need the User Requirements for all PT colors (and graphics alltogether), before flying head on into 'solutions'. Anyway, there is no deadline so we have time to build this part properly and fruitfull.-DePiep (talk) 20:15, 21 October 2020 (UTC)

@DePiep: well, since we're discussing criteria, it will be nice if you tell us what is missing. Because otherwise, it reads like this: we have to stay put for now until we formulate better criteria, I know there could be better criteria, but I will not expand upon this thought.

What kind of science communication are we talking about? You previously argued that there should be no dependance on cultural issues in a coloring scheme. Have you changed your position since then or are the two statements reconcilable; if so, how?

What is User Requirements? Googling does not return a satisfactory answer, so I'll gladly listen to what I may not know.

Other discussions on this page do not directly affect this one. The only thing that matters is the outcome of the group 3, nonmetal, and block discussions, for which we are waiting. The rest does not have anything to do with this one, so they are thankfully not a factor. If some other outcome pops up, it will matter too, but not before it does.

There is indeed no deadline per se, Misplaced Pages is always work in progress. Yet it doesn't mean we can't do anything now. If it indeed takes loads of time to create a perfect table, it doesn't mean we can't do anything in the meantime; if it did, that would be dawdling. Again, my end goal is replace the present coloring scheme for something better, and I hope you share that goal, so that you can help us formulate criteria for what is better and perhaps even create the scheme we'll end up picking. If you can't for whatever reasons devout time now to creating a new scheme, that's fine, too; after all, some scheme is passed before you can join in on the fun, you can always ask to consider your scheme, too, once you present one, and there is (and should be) no way of stopping you from doing that. No scheme will ever be final.

However, if you don't present one, will not aid the discussion of formulating criteria for a future scheme, and will ask that no change is made even though you previously agreed the current scheme was not particularly good, other editors will likely think this is counterproductive behavior, and will likely act upon it. You expressed interest in creating a new scheme in 2016 and said it was in your to do list in 2017; however, it's 2020 now and despite all the "time to build this part properly and fruitfull," we haven't been presented a scheme yet. I do want you to help us create a better scheme, possibly even create the one we'll go with; by all means, please go ahead. However, if, all things considered, you can't aid that, then I'll ask you to at least not obstruct creation of such a scheme by other editors, and I expect understanding in asking for that from other editors.(retracting this comment since this worry turned out to be unfounded)--R8R (talk) 14:29, 25 October 2020 (UTC)

@R8R:. First reply: I don't like the tone and approach of this post. It is trying to tie me to quotes (old, and out-of-context), edits not made (really, why did you not restart the 2016 discussion? Why do you keep suggesting that it was frustrated instead of not well-fleshed-out?). And no, contrary to what you say it's not affected by just one discussion here. By now, all discussions on this are contaminated with ANI-reports. See, before I can respond in content, I have to weed out aspersions and derailed discussions. -DePiep (talk) 17:12, 25 October 2020 (UTC)

I admit that I did think, when I first read R8R's comment, "oh no, this is going to start things again", because of the last sentence. I would probably have felt a bit annoyed if it were directed at me. It seems to me that User:DePiep is perfectly willing to start now; he just seems to want user requirements to be fleshed out before a solution is reached, but that seems to be part of a possible road towards a change. If I have read him wrongly, then I apologise and ask him to clarify what he meant. So I am unsure if the characterisation of obstruction is accurate, and I also wonder if it was appropriate. Double sharp (talk) 18:12, 25 October 2020 (UTC)

@R8R: Forgotten ping, sorry. Double sharp (talk) 18:17, 25 October 2020 (UTC)

About right, Double sharp. The "willing to start now" might need a pinch of salt, because other discussions need attention too.

Then, about "requirements". In the design process, there are two poles to recognise: the science & content we want to show versus the good-webdesign we want to apply. Example details of the first, content: (7-8-9)+1unk cats; express other properties (SoM, origin, today by fontcolor and borderstyle); other info (say make possible to clarify electron config with support colors). Example details of good (web)design: sure font contrast per w3c (black+wikilinkblue or more?); colorblindness (CB) awareness; what to hyperlink; and prime legend-functioning: ability to connect cell bg-color<-to->legend location two-way, and also between cells to distinct colors; understand what the Reader of this encyclopedia expects (subconscious too), and what helps them, and even invites them to discover more. These examples are just for starters. These poles in general have competing requirements, and each requirement (whichever pole) will reduce the degrees of freedom of design. Consider that, likely, "9+1" will make it impossible to serve all i.e. expect a need to compromise *somewhere, somehow*.

Now getting the requirements (desires, wishes, aims, options) clear & agreed upon is not a one-dimensional route, and so not suitable for a discussion/thread like this page uses (I'd think: per pole a WP-page+talkpage). Each set of requirements needs thought development, establishing principles, instruments to work with, check options. Over this, it requires a design attitude from those involved, willing to communicate and accept, to learn and understand, to explore new areas of knowledge. (For example, I am thinking about inviting WMF webdesign people, to help solve our quests; like a "zoom-in/zoom-out option" to go from cell<->PT, would be great ah!). So far for step 1: 'requirements'.

After this, the design can start. It is a pilgrimage with uncharted routes, guided by stars. In the end we will meet atop a hill, together with thousands of readers, to enjoy the many shining bright periodic tables above us—the ones we thought were the stars guiding us all along. -DePiep (talk) 20:27, 25 October 2020 (UTC)

First of all, Double sharp, thank you for stepping in when you sensed the discussion was getting heated. May I ask you to stick around this discussion until we've finalized the requirements?

When I proposed in the previous section we invent a new coloring scheme, DePiep said we should discuss the requirements first. So I set up this section to talk about requirements. I would normally expect to see here some actionable suggestions, ones we could write down and refer to later, but what I saw instead is some vague description of how the problem is difficult (at least, that's what it appears to me: I could not extract any proposition from it one could say yes or no to), but at the same time, I was reminded that we need user requirements. That is precisely what this section is for. I welcome what explanation DePiep has just provided. I sort of wish it was provided the first time I asked, but late is better than never.

DePiep, I have a question. You mention there are other things you are preoccupied with and you cannot devout all of your attention to this quest. We don't know how long it will take to have you turn all of your attention to this quest. We don't know how long it will take to formulate the perfect requirements. We don't know how long it will take to produce a perfect table based on these perfect requirements. This could take a lot of time, so the question is this. Would you agree we try to create a new coloring scheme in the meantime, before the perfect one has been produced, and not oppose adoption of such an interim scheme unless there are ways in which it is worse then what the current scheme? If the answer is yes, then of course all of my obstruction concerns will be clearly devoid of any substance, and I'll gladly take that word back.

Since there were two questions pointed at me, I feel obliged to answer them.

• Why did I not restart the 2016 discussion? -- the simple answer is, I did, back in 2017. I even asked this question: "Could you explain to the amateur that I am what's wrong with them ?" I didn't get a sound answer for that one. What I did get is that saying they were not perfect, and no actionable comments. I was hyped up back by what you could produce then, but this hype has waned now that it's been three years since then and nothing has been exhibited, and it's still far from clear when it will.
• Why do I keep suggesting the 2016 proposal was frustrated instead of admitting it was not ideal? -- the answer is simple, too. It was a clear improvement compared to the old scheme, and it was frustrated because it was not perfect even though it was an improvement. In fact, the fact that it was an improvement is something you mention in the 2017 discussion, too. But to quote, you said, "please do not propose that" (italics in original), because the 2016 proposal was "not perfect." I didn't press for adoption of the proposal at hand back in 2017 because I thought you'd create an even better scheme. Three years later, nothing has happened, and I begin to think we could've spent those years with a better scheme.--R8R (talk) 21:54, 25 October 2020 (UTC)

@R8R: Thanks for your kind words; I will have a time shortage, but I will try to at least stick around at the project page issues. I confess that I am not 100% sure about starting to create a new colour scheme in the meantime, when we have not even gotten to the stage in our plans where we arrive at deciding what categories there are, but for me it is simple: if that is what a majority of project members want, then so be it. Double sharp (talk) 22:18, 25 October 2020 (UTC)

Thank you very much! I'm reassured by that.

The point in having an interim scheme is simple. The way DePiep describes it now sounds impressive, but what description I heard in 2017 sounded impressive, too, but it didn't result in anything. If I were confident that a coloring scheme would actually be created this time, then this would not be necessary. I was confident back in 2016 and 2017 that a new scheme would be produced, and I didn't press for the proposal at hand precisely for that reason, but in the end, nothing was presented, so there's a chance this might happen again. (I am absolutely sure DePiep means it now, but I'm just as sure they meant it back then, and we didn't get anything.) I think there shouldn't be a problem recognizing an interim scheme in case the creation of the perfect scheme takes far too long again; after all, if the perfect scheme is created, it will likely supersede what interim scheme there will be.--R8R (talk) 22:39, 25 October 2020 (UTC)

DePiep, I have posted to user talk:R8R about the tone of his post, which I agree was inappropriate. Would you be able to look past the tone and comment on the questions that R8R raised that you see as pertinent to this discussion? Thank you. EdChem (talk) 04:44, 26 October 2020 (UTC)

• Fair enough, R8R. This week I will publish a structured subpage to discuss and develop the whole issue of periodic table graphics (say, presentations). PT content topics (like which categories to cover? do blocks instead?) belong here at WT:ELEMENTS. From there too, we will look at the feasibility of an early new color scheme.

I will report here. Anything to clarify? ​​​​ -DePiep (talk) 19:15, 26 October 2020 (UTC)

Great; I'm happy to hear that. I am also happy to conclude that my worry about obstruction turned out to be unfounded, and as promised, I'll gladly retract it.--R8R (talk) 10:36, 1 November 2020 (UTC)

Due to distractions, I have not been able to meet my stated one-week goal. Personally, I am fine. -DePiep (talk) 22:02, 5 November 2020 (UTC)

Astatine

I suspect that there are many readers who vaguely recall their high school chemistry who would be surprised to see astatine classified as a metal. Am I correct in saying that astatine shows properties that are halogen-like and also that are metal-like? WP's article lede states that "most of compounds resemble those of iodine" and that it is "usually classified as either a nonmetal or a metalloid." Does the article need an update or is putting it as a metal another choice where multiple perspectives are reasonable? I note that we also state that "astatine is the least reactive of the halogens," citing an article from 1959. Is it predicted Ts would be less reactive still? Or not a halogen? Should the table or PT article cover the classification of elements like At and the more recent discoveries? I know the hassium article includes that the properties were consistent with its expected position in the PT, for example. Would a reader expect Og to be a noble gas? If we are talking about changes to the PT article and display table, I think it's worth looking at other potential topics / issues. Thoughts? EdChem (talk) 21:41, 18 October 2020 (UTC)

Should this not be a ==-level section? -DePiep (talk) 21:52, 18 October 2020 (UTC)

I was ambivalent about where to put this... I have no objection to it being changed to double-equal header rather than a triple-equal.  :) EdChem (talk) 21:56, 18 October 2020 (UTC)

@EdChem: (edit conflict × 1) Thank you so much for keeping each topic in a separate section! ^_^ Trouble with astatine is that indeed it shows both halogen-like and metal-like properties. If we factor in predictions as well – condensed-phase astatine according to calculations would be metallic. I think the problem is that for most chemists At is a nonentity and so if it is thought about at all, it is thought of as "well, it would be the fifth halogen" and packed off to the nonmetals, so that's where you will normally see it. Which to some extent it is, but sources focusing on its chemistry (which understandably are not that many) tend to note that it is surprisingly more metallic than you might think and has similarities to Po also in that way. The low concentrations you have to work with no doubt make the interpretation worse, especially when you are inevitably using iodine as a tracer which is slightly different (it was thought for a while that AtO₃ was being formed because astatine was being carried with iodate – actually it turned out to be an At iodate salt after all IIRC). So I think you'll find that multiple perspectives are common in the literature, and then we have the problem on which sources to weight more.

As for Ts: it is not even clear if Ts is a halogen in the first place. The problem is whether "halogen" means a category of similar elements that implies nonmetallicity (in which case probably metallic Ts with little inclination to form tennesside anions is a kind of lame inclusion), or the whole group starting with fluorine. The IUPAC Red Book isn't helpful here because it lists only F through At but was written at a time when Ts had not been discovered. Similar issue with whether Og is a noble gas or not: judging by some articles, it might not be.

You may begin to see why I eventually started thinking that maybe it's best not to colour categories at all if so much of the p block has different sources saying different things about metallicity, no one is sure if "halogen" and "noble gas" mean the group or just part of it, no one is sure if "transition metal" includes group 12, no one is sure whether to include metalloids or just to use metals and nonmetals, no one is sure exactly how the nonmetals should be divided or even if they should be divided and what they should be called as a whole when the noble gases are excluded, and no one is sure what to call the metals in the p block. Most tables do go beyond blocks alone, but a significant minority stops there, and at least that's one thing people are relatively sure about. But maybe you have another way to fix this problem and retain colourings, in which case I'm ready to hear it! ^_^ Double sharp (talk) 22:02, 18 October 2020 (UTC)

@EdChem: Immediately following its production in 1940, early investigators considered astatine to be a metal. No surprise there considering iodine looks like a metal under white light and is a semiconductor with a band gap of about 1.3 eV. Batsanov in 1971 gave a non-relativistic calculated band gap for astatine of 0.7 eV i.e. a semiconductor with a metallic appearance. Relativistic calculations in 2013 predicted astatine would be a full-blown fcc metal. This article has been cited 35 times without dissent.

As far as the p-block is concerned, there is no drama and no fuss. We know from RS that the elements commonly recognised as metalloids are B, Si, Ge, As, Sb, and Te. To the left are the post-transition metals. In the literature, group 12 are treated as TM or PTM on about a 50-50 basis. Since group 12 have a predominately main group chemistry, not to mention the dramatic weakening of physical properties going from group 11 to 12, we count the latter as PTM. To the right of the metalloids are the noble gases, and the halogen nonmetals. The residual nonmetals, H, C, N , O, P, S, Se exhibit a rich array of shared attributes and some or all of them have been referred to by as many collective literature-based category names, some of which are not unique to the nonmetals involved, including:

• biogens;
• CHONPS nonmetals;
• intermediate nonmetals;
• light nonmetals;
• moderately active nonmetals;
• organogens; and
• other nonmetals.

Some other terms that are about to appear in RS are:

• coactive nonmetals;
• moderately active nonmetals (again, and as also suggested to me by another chemist);
• pre-halogen nonmetals;
• rail nonmetals (refractory and interstitial light-life); and
• Goldilocks nonmetals.

The last of these arises since the seven nonmetals concerned have properties that are neither too extreme, nor too weak, but just right to support life as we know it. Further, each of them nonmetals have their own WP biogeochemical cycle article. Sandbh (talk) 11:45, 19 October 2020 (UTC)

@EdChem: As a chemist, how many of these names given by User:Sandbh would you recognise or understand if presented without an explanation? And would you mentally read them as meaning exactly the set {H, C, N, O, P, S, Se} that Sandbh is referring to, or as some other set, or just as a set with some fuzzy boundaries? I ask this just as a rough gauge of the prevalence of these names. Double sharp (talk) 17:48, 19 October 2020 (UTC)

I'm curious about this, too. I said before that I didn't think there was an easily recognizable name that would point to this set of elements, and I still have this feeling, so I'd greatly appreciate another opinion about this that could point out whether I am right or wrong.--R8R (talk) 19:49, 19 October 2020 (UTC)

(P.S. Second question naturally contingent on whether those names are recognised/understood.) Double sharp (talk) 20:05, 19 October 2020 (UTC)

@Sandbh: Which of those twelve names do you support Misplaced Pages showing for {H, C, N, O, P, S, Se}? (Possibly more than one.) And are there significant differences in how much support there is in the literature for each of them? I ask to get a clearer idea of your position. Double sharp (talk) 20:59, 19 October 2020 (UTC)

A better quote about astatine from C&EN News rather than just a chemist's blog: "is astatine more like a halogen or like a metal?" So there's proof that it is not clear cut if "halogen" is a group name or a category name, and that it is not even clear cut if At is a halogen in the first place. Double sharp (talk) 20:52, 19 October 2020 (UTC)

Some answers, which are my opinion / experience and thus may differ from the literature (though likely not from common usage):

• I don't recall having seen most of these names and I would stop and wonder what most of the modifiers of "nonmetal" actually meant.
• I certainly am familiar with CHONPS but think of it being about the non-metals that are essential for life and also as a way for students to learn about the composition of major biomolecules. Carbohydrates require CHO, though of course some also have N (like glucosamine). DNA / RNA require CHONP, proteins require CHONS (though there are some with Se too, so I am not surprised to see it appearing). Like most such learning tools, it is a guideline to use with flexibility. After all, there are biomolecules that contain I, and chloride ions are common in intracellular and extracellular fluids – so I can see a reason for it to be taken as a reference to those two halogens as well.
• On At being excluded from the halogens on grounds of chemical properties but included in the term "group 17 elements," I can see the appeal, and it becomes stronger when extended to Ts which is likely to be much more metallic in properties (assuming we ever can investigate them)... but on the other hand, the terms chalcogen and pnictogen already cover both metals and non-metals (as I understand them) so is there a reason for a different approach to halogens? But, going back to the first hand, is a term like "noble gas" appropriate for Og if it turns out not to be gaseous? Further, we already have a significant known chemistry of xenon and similar chemistry can reasonably be anticipated for Rn or Og.
• Sandbh, I accept that the chemistry of astatine has significant metallic character, but I am not sure that you recognised my points:
  • Even if At should be categorised as a metal on the WP PT, will it be a surprise to readers and thus warrant some comment in explanation?
  • Classifying At as a metal is inconsistent with some statements that I quoted from our astatine article, and so some changes there or to our PT article or both may be warranted?
• As a general observation, when I see comments that address situations where there is ambiguity or disagreement or the like and yet the comments read like there is no alternative view possible, I tend to become more doubtful and questioning. When !voting is an exception (at least somewhat) because advocacy for a perspective is understandable there, we are trying to develop appropriate encyclopaedic content and that requires consideration of the breadth of views from RS, etc. Now, someone well across the literature (and in this area, that is not me) may well have already considered issues like DUE and RS etc and so can jump direct to a balanced summary. Just a thought worth bearing in mind, IMO, for whatever that is worth.

EdChem (talk) 00:10, 20 October 2020 (UTC)

@EdChem: Will respond to the rest later, but according to predictions, it seems Og is probably neither noble nor a gas. (Two links; it seems to be a reactive semiconductor with common +2 and +4 states. I don't think either raised the comparison with known elements, so this is just OR for the talk page, but that sounds to me way more like germanium or tin than xenon. ^_^) Not that I think we'll get to experimentally test it anytime soon. As for chalcogens, I recall that Droog Andrey mentioned before that in Russian texts, polonium's position as a chalcogen is somewhat ambiguous and so is astatine's as a halogen, which may come from the "chemical properties" urge (don't know about pnictogens). I think that there are a lot of alternative views in the literature, and although I certainly prefer some to others, I think that WP should instead clearly reflect the situation that the literature is not decided. And I am concerned that any explicit colouring of categories makes it harder to show that undecided situation, particularly since you would need footnotes for nearly every p block element. Double sharp (talk) 00:25, 20 October 2020 (UTC)

@EdChem, R8R, and Double sharp:

The general reader. I'm reminded of EdChem's comment, somewhere, that we're writing for the general reader. In this context it doesn't matter what a chemist thinks.

What does science say? EdChem, I support your approach of considering what the science says, rather than what our personal preferences are.

Fuzzy thinking. On the science front, fuzzy concepts are, as I understand it, a part of chemistry and explain why, to some extent, chemistry cannot (not yet, anyway) be fully reduced to physics. That said, sharpish and fuzzy categories have always played a part in the development of science, generally. In chemistry there are fuzzy concepts like acidic-amphoteric-basic; metal-metalloid-nonmetal; or ionic-polymeric-covalent. Despite their fuzziness, these basic groupings include some of the most powerful ideas in chemistry.

The breadth of a discipline. I cannot speak for chemistry but in my own area of professional expertise (strategic people management; learning and development), I know a lot and I don't know it all. And I was never worried about unfamiliar jargon; there are too many models, theories, luminaries, and sub-disciplines, to be across them all. The good thing was I never stopped learning. In strategic people management you can always fall back on something called the people management life cycle (capability > raise > train > sustain > capability > repeat). Anything else you either learnt doing your post-grad, or you pick it up along the way, as required. In chemistry, as far as I have read, the PT serves as the organising or learning icon, plus whatever you learnt at university, and you pick up the rest along the way, as required.

H, C, N, O, P, S, Se. The WP situation strikes me as being akin to post-transition metal territory. There are several nomenclature possibilities found in the literature. Scientifically, my pick would be moderately active nonmetals. It’s an ugly, clumsy and relative term. But it’s generic; not tied to any particular sub-discipline, like biochemistry (important as that is); doesn’t have significant overlap issues; and is conceptually anchored in the left-right activity progression seen across the period table, as widely recognised in the literature. For the nonmetals this of course refers to the chemically weak metalloids to the left and the highly active halogen nonmetals to the right.

I no longer support other nonmetals. The great majority of Ngram hits are to vague and irrelevant expressions like “plastics and other nonmetals”.

Ambiguity. When it comes to situations where there is ambiguity or disagreement or the like I strive to make reference to all the possibilities. See, for example, metal; nonmetal; post-transition metal; metalloid; heavy metals; and lists of metalloids. Sandbh (talk) 10:55, 20 October 2020 (UTC)

Duplicate article

Introduction to superheavy elements is a duplicate of Introduction to the heaviest elements; only the latter is transcluded in element articles. –LaundryPizza03 (dc̄) 16:47, 22 October 2020 (UTC)

A WikiGnome writes

One interest of a fellow gnome, Certes, is fixing bad links to WP:PTOPICs. I lunged with krypton, lithium and neon, and he fixed 150-odd bad links. He parried with chromium, lead and palladium. I riposted with copper, gold, radium and silver. (Discussion here.)

Are there any other elements which may have collected bad links? Narky Blert (talk) 20:37, 28 October 2020 (UTC)

@Narky Blert: None very readily come to my mind unfortunately – but it looks like some elements have associated disambig pages like

As I understand the question, I think it refers to resolving links unintendenly linking to the main topic Krypton while Krypton (TV series) should be the target . So ELEM people are invited to look for WP:DAB-misguided incoming links.

If I am correct in this, you and your friend are doing a great job! From our point of working (elements), we see this: Krypton has 1000–1500 incoming links . Shoud I check and fix them? Then think about the uranium or hydrogen numbers. So: please continue! (I remember re Congo: the nice part was, researching the intended articles. nice. And skip one if its a headache). -DePiep (talk) 21:25, 28 October 2020 (UTC)

Yes, the aim is to make many minor fixes such as this. (The access-date genfix is incidental.) Working through Krypton and others mentioned here may no longer be very productive as we already fixed the easily found errors but other elements may have problems to find. I didn't have the patience to check every link; I've been searching with filters both positive (e.g. linksto:krypton superman) and negative (linksto:krypton -noble -element -argon). I've had at least a cursory glance at the first 30 elements (H–Zn). Certes (talk) 21:45, 28 October 2020 (UTC)

You mean fortunately... There's little point in checking every incoming link when the vast majority will be perfectly good. The most productive method is to look at articles where bad links are both likely and easy to find. (London is in the "too difficult" pile.) I have a "sore thumb" style whereas Certes has a more structured one. Tetrahedron/Tetrahedron is a well-known problem; I started thinking about other possible ones relating to chemistry when I came across an article with a short list which included a DABlink (which was how I found it), Fiat (which was how I solved that problem) and Proton (which jumped out at me). Narky Blert (talk) 05:22, 29 October 2020 (UTC)

RFC proposed: Nonmetal categories

​​​​​​ Colleagues, I intend to put the following RFC, at Periodic Table talk:

Should the WP periodic table show 2 or 3 nonmetal categories(?):

2	3
• Noble gases: He to Rn • Reactive nonmetals: H,C,N,O,F,P,S,Cl,Se,Br,I	• Noble gases: He to Rn • Halogen nonmetals: F,Cl,Br,I • CHONPS nonmetals: H,C,N,O,P,S,Se

I’ll draft some accompanying notes.

Comments please. Thank you. Sandbh (talk) 08:14, 29 October 2020 (UTC)

(I understand you ask for early comments here).

I hope you also spend arguments on the strengths of the two 'new' categories. As in: strong internal, common properties (the category characteristics), and distinction re other categories (otherness). This has been mentioned before on this page.

Minor idea: maybe you can 'name' the second category more completely 'CHONPSS', we should consider the name might stick ;-) and so be more to the point. (Or SCHONPS? CHNOPSS?). As said: minor -- and a bit funny too. -DePiep (talk) 18:30, 29 October 2020 (UTC)

Is there a WP:RS which says 'CHONPS'? or any variant thereof? Unless there is, it would be WP:OR/WP:SYNTH. Narky Blert (talk) 20:43, 29 October 2020 (UTC)

Chalcogen is a long-established name for the non-metals in what used to be Group VI. Narky Blert (talk) 20:55, 29 October 2020 (UTC)

@Narky Blert: re 'is there a RS for "CHONPS"?'. If it is descriptive, we don't need a source nor OR. However, then we'd have to write 'CHONPSSe' in full. Despite what Sandbh already wrote, below, I think we should use this correct full list. -DePiep (talk) 23:48, 30 October 2020 (UTC)

@DePiep and Narky Blert: Thank you.

1. Yes, I'll add some notes about the two new categories, including along the lines you requested.

2. A funny thing: I looked at the 2 column in the above table and wondered how so many nonmetals could be "lumped" together in one category, given their diverse attributes.

3. I feel there's no need to e.g. add "Se" after "CHONPS", since S can be read as S and Se. Not forgetting S and Se are in the same group, and share an appreciable number of properties. For example, selenium is found in metal sulfide ores, where it partially replaces sulfur; both elements are photoconductors—their electrical conductivities increase by up to six orders of magnitude when exposed to light. The two nonmetals form about a dozen chain and ring entities of composition S₍₁₋₇₎Se₍₁₋₆₎.

As well, CHNOPSSe doesn't sound or look quite as good.

4. There are some citations in the table. Note the three variations: CHON (this one is very old); CHNOPS and CHONPS.

5. We have an article on the CHON elements. This article, sans attribution, notes "The acronym "S.P. Cohn" was also used in high school biology classes to represent the six chemical elements."

6. Here is the link to the Wiktionary entry.

7. The WP PT is a metallicity based PT, showing the L−R progression in metallic to non-metallic character, so a group name such as chalcogen is not so relevant here.

8. I've asked some chemistry teachers if they use CHONPS. One said, "Yes, I have used CHNOPS for years." @EdChem:, a chemist, is familiar with it too. --- Sandbh (talk) 03:39, 30 October 2020 (UTC)

Final RFC

Q1: Should the WP periodic table show two, or three nonmetal categories, as set out in Table 1?

Q2: If you support three nonmetal categories, what name/s do you support for the third category, as set out in Table 2? You can pick more than one.

Table 1: Two or three nonmetal categories?

Two	Three
Noble gases: He,Ne,Ar,Kr,Xe,Rn Reactive nonmetals: H,C,N,O,F,P,S,Cl,Se,Br,I (existing category)	Noble gases: He,Ne,Ar,Kr,Xe,Rn Halogen nonmetals: F,Cl,Br,I Your pick/s from Table 2 nonmetals: H,C,N,O,P,S,Se

Table 2: Category names found in the literature for
nonmetals other than halogen nonmetals and noble gases

Name	Comment	Name	Comment
1a. Bioelements 1b. Biogens 1c. Biological frame-work elements 1d. Primary bio-essential elements	1a. H,C,N,O,P,S,Se 1b. H,O,N,C (1873) or H,C,N,O,P,S 1c. H,C,N,O 1d. C,N,O,S,P	8. Moderately active nonmetals	Elaborated below Probably the most easily understood category name for the average chemist
2. Carbon & other nonmetals	Excludes H, which is in its own category	9. Organogens	Overlap into some halogens
3. CHNOPS	Also CHONPS; predecessor “CHON” dates from 1865	10. Orphan nonmetals	(juvenile nonfiction)
4. Essential elements	Depending on the source, essential (nonmetal) elements include from 5 to 9 of P; HCNOSCl; F(?)SeI; Si.	11. Other nonmetals	“Other” means “existing besides, or distinct from that already mentioned"; "auxiliary", "ancillary, secondary" (2 ed. OED; thesaurus entries for "other")
5. Intermediate nonmetals	Excludes O	12. Redox nonmetals	H,C,N,O,S,Se although in text this class of nonmetals is given as H,C,N,O,P,S. The halogens F,Cl,Br,I are "extreme nonmetals". (2001, pp. 10–11) Elsewhere, S, Se and the halogens are referred to as redox nonmetals (p. 489)
6. Light nonmetals	Overlap with He, Ne, (Ar); and F, Cl, (Br)	13. SPONCH	Listed in descending order of Z The S could be read as Se and S, being in the same group and sharing many properties Optionally "SeSPONCH"?
7. Nonmetals	Implies or suggests that halogens and noble gases are not nonmetals Can include Se e.g.

Preamble

• The aim of this proposal is to provide more information about the elements in this part of the Misplaced Pages periodic table.
• The existing category of "reactive nonmetals" overlaps with the noble gases. For example, xenon reacts with F, Cl, C, N, and Au, and itself, among others. Krypton is less reactive; radon would be expected to be more reactive.
• After the sharply delimited halogens and noble gases, there is no standout category name in the literature for the remaining nonmetals: H, C, N, O, P, S, Se. A similar situation occurs with the post transition metal category, with at least 17 alternative category names found in the literature.
• Category boundaries can be fuzzy, and overlap in some cases. Chemistry has all sorts of fuzzy definitions often leading to unnecessary disputes concerning the periodic table e.g. re H, He; and Group 3.. Other fuzzy concepts include e.g. acidic-amphoteric-basic; metal-metalloid-nonmetal; or ionic-polymeric-covalent.
• A list of the shared properties of H, C, N, O, P, S, Se is here. Table 3 shows the delineations between the categories of nonmetals, in terms of ionisation energy, electron affinity, and electronegativity. The metalloids, which have a predominately nonmetallic chemistry, are included for comparison.
• Strictly speaking, for name #12 "SPONCH", the nonmetals H, C, N, O, P, S, Se ought to be referred to as the SeSPONCH nonmetals.
  • Such a name is not found in the literature so it could only be regarded as a descriptive term.
  • In the literature, "SPONCH" or "CHONPS" appear to refer only to H, C, N, O, P, S.

Survey instructions

1. Anything beyond a simple !vote for either two categories; or three categories (and your Table 2 pick/s), should be placed in the "Discussion" sub-thread, following.
2. If you support three nonmetal categories, please include the number/s of the Table 2 name/s you support.
3. The survey will be closed after 30 days by an admin, unless it is reasonably apparent that consensus has been established before then.
4. If the "three categories" option achieves consensus, the choice of name with the most votes "wins". In the event of a tie, there would be a follow-on run-off, after a due period of discussion.

Survey votes

…

Discussion

…

Comments on draft RFC

Narky Blert

CHNOPS looks to me like a wholly anthropocentric, and therefore arbitrary, selection, based on biology not chemistry. 99.9% or better of biologically important compounds (on Earth, at any rate) contain nothing else. Most of the remainder include a metal cation. The number of compounds which contain any other element covalently bound is tiny. All the ones I can think of (other than the I-containing thyroxine) are peculiar specialist defences against predation, or are manmade pharmaceuticals or things like nerve agents. How many biological molecules can you think of which contain covalently-bound B, Si, Ge, As, Sb, Se or Te? Narky Blert (talk) 19:56, 30 October 2020 (UTC)

@Narky Blert: Thank you.

There are a couple of interesting considerations here.

1. The biogeochemical or toxicological (e.g. nerve agent) properties are but one facet of the CHONPS or SPONCH bunch, where S includes S and Se.

2. While the noble gases, as elemental substances, can be characterised by their invisibility and torpidity, and the halogens by their variegated appearance and acridity, the Se-S-P-O-N-C-H set exhibit the following characteristics:

• Sub-metallic (C, P,^ Se), coloured (S) or colourless appearance (H, N, O), and a brittle comportment if solid.
• Being sandwiched between the strongly electronegative halogen nonmetals and the weakly nonmetallic metalloids, their net physical and chemical character is moderately non-metallic. See Table 2, here.
• Pronounced vertical, horizontal and diagonal relationships.
• An overall tendency to form covalent compounds featuring localized and catenated bonds as chains, rings, and layers.^^
• Prominent organocatalytic, and energetic (explosives and combustion) aspects.
• In light of their relatively small atomic radii and sufficiently low ionization energy values, a capacity to form interstitial and refractory compounds.

^ Black P, the most stable form in ambient conditions, is these days easily prepared.

3. I don't make up the nomenclature. I can only go by what's used in the literature.

I used to think that e.g. biogen nonmetals, was too biologically focussed. But I finally got that this was just a personal preference, based on what I like or dislike, rather than a scientific decision based on scientific terminology, as per the advice User:EdChem has given us. The first time I saw a 32-column PT with a split d-block, I thought it was ugly and loathsome, and unacceptable. Now I understand that this was on account of "values→beliefs→rules" perceptual filters operating on auto-pilot. Now I know how to turn off my auto-pilot, and set aside my values→beliefs→rules, and just look at and accept what the science says.

4. Our periodic table is not just a chemistry-based table, so to speak, although chemistry is certainly a biggie. Other periodic-table fields of relevance include e.g. physics; biology; metallurgy; cosmology; geology; materials science, and so on.

5. I'm all ears as to a "better" name, based on the 11 options available to us.

6. Off hand, I know some sea sponges have endoskeletons comprised of SiO₂. Among V series nerve agents, VX is the most studied: C₁₁H₂₆NO₂PS. The selenium analogue of VE is selenophos C₁₀H₂₄NO₂PSe. This is said to be more potent than VX. The article "Why nature chose selenium" gives a history of the important discoveries of the biological processes that selenium participates in, and a point-by-point comparison of the chemistry of selenium with the atom it replaces in biology, sulfur. This article discusses the role of boron in metabolism, "that render it necessary for plant, animal, and human health." As I understand it, the chemistry of B, Si, and Se tends to be characterised towards the covalent patch of the field of bonding possibilities.

--- Sandbh (talk) 01:44, 31 October 2020 (UTC)

@Sandbh: Some terrestrial plants incorporate SiO
₂ - two reviewish articles 1 and 2. My guess would be that all the chemistry involves compounds with Si(IV)-O bonds. Narky Blert (talk) 06:58, 31 October 2020 (UTC)

DePiep

• Note #DePiep-01: using "category" in articles.

The word category has no specific meaning in (PT-)chemistry, unlike group (ouch, twice), period, and block. So far, until ca. mid-2020, we have used it internally only on talkpages etc. But recently it has been added in FA-article TOC-level: see Periodic table § Categories. This might be too much of a stretch (OR?). Hey, there is not even an article Category (periodic table).

I add that this categorisation used to be by 'the YBG set of requirements': "all elements, once, and there be coherence" (my short take). In the current (2019) form, this leaves out sets like Rare earth metals and Coinage metals. Later on in this discussion we might meet this issue: random, non-YBG categories to deal with. (Classifications is a good word b/c it has reason; set is really ok to make any list).

My long term question: do we keep using category in articles for this classification-by-YBG-terms? -DePiep (talk) 00:28, 31 October 2020 (UTC)

​@DePiep: The word category is found three times in the IUPAC Red Book, including:

"In particular, alcoholates, thiolates, phenolates, carboxylates, partially dehydronated amines, phosphanes, etc. are in this category." (p. 151)

Fowler's modern English usage (1998) says:

"category. To begin with, restricted to its original philosophical meaning, ‘one of a possibly exhaustive set of classes among which all things might be distributed’ (COD); later (attributed to Kant) ‘one of the a priori conceptions applied by the mind to sense-impressions’ (COD). These philosophical senses made their way imprecisely into general use from the 17C. onward, and settled down with the broad meaning, 'a class, or division, in any general scheme of classification’. This more general sense, though objected to by Fowler (1926) and others, is now uncancellably established. Examples: She placed them in two categories: the honest imbeciles and the intelligent delinquents—O. Manning, 1960; He had had the whole of creation divided into two great categories, the things he was for and the things he was against—M. Frayn, 1965; ‘I hope you aren't a clergyman.' She said it with real vehemence, as if it was the one category of person she was not prepared to have in the house-A. N. Wilson, 1981"

Here in WP, we refer to "Chemistry" as a category, with 72 subcategories. --- Sandbh (talk) 03:02, 31 October 2020 (UTC)

Yes, yessss, YES! As you say: "category" in chemistry literature is different and more wide than the current, internal enwiki meaning. -DePiep (talk) 23:53, 7 November 2020 (UTC)

R8R

There is no comment on the content of the RfC proposal I could give (I think it's fine), but I am wondering what Double sharp has to say. My understanding is that Double sharp has effectively suggested there should only be four categories, namely, the s-, f-, d-, and p-blocks, and expressed his desire to have an RfC on that topic, too. That proposal directly conflicts with this one, and my thinking is, there should ideally be an attempt to coordinate the two given that they are mutually exclusive.--R8R (talk) 12:08, 1 November 2020 (UTC)

@R8R: The two proposals aren’t necessarily mutually exclusive. There are two ways of achieving both solutions: categories and blocks; or blocks and categories, as I suggested, here. Sandbh (talk) 12:43, 1 November 2020 (UTC)

I have my doubts about that. Double sharp's point was not that blocks should be introduced, his point was that blocks should be introduced instead of the current categories. There is no way the two can go together as far as I can see, which is why I'm asking you to coordinate your proposal with his.--R8R (talk) 11:33, 4 November 2020 (UTC)

I confirm that User:R8R is exactly right. For me, the categories should not be used to colour the table at all. In my view, they can be mentioned in the article, mentioned in the exact infoboxes, along the lines of "Selenium is a chalcogen. It is most often considered a nonmetal, but has sometimes been referred to as a metalloid or more rarely as a metal." But I am wholly opposed to any single colouring of categories because to me it fails to reflect the real source situation, which is more along the lines of the quote I just said. That is what will be seen if we take a sweep across many sources, at least as long as we don't just cherry-pick just the ones that look like they support the particular category du jour. As far as I can see, this proposal of mine is exactly mutually exclusive with the two detailed here. I personally would not have wanted to go for this now when the group 3 discussion is not quite finished yet (we already have majority for changing back to Lu but discussion with R8R is still going), but if it is to go forth, I agree with R8R that the "blocks alone" proposal should absolutely be included.

As well, the statement Anything beyond a simple !vote for either two categories; or three categories (+ your Table 2 pick/s), should be placed in the "Discussion" sub-thread, following in the proposal looks to me quite like an attempt to sideline other proposals. As far as I am aware, this is not usual practice on WP, where it is reasonable and possible to !vote for neither option presented in a survey and suggest one's own. I hope this is not the case. Double sharp (talk) 11:42, 4 November 2020 (UTC)

@Sandbh: I am seriously concerned about the changes introduced to the draft since I commented on it. The idea that a vote for a different change the one being implemented can be still counted as a vote for a change is very disturbing. Votes may not be counted the way they were intended to be counted. That's a serious problem.

There are better ways to conduct a multiple-choice poll. For example, when New Zealand was considering a flag change, citizens first voted on which new flag should be adopted if there was to be a change at all, and then they voted on whether there should be a change to that selected flag. This seems much fairer to me; however, I am concerned that participating a two-stage RfC is a bit much to ask from outsider participants, which is why I think the first round (selecting the favored option) should happen within our project, and then the agreed upon name should be offered to outsider participants. It was my impression this was what was going to be proposed the first time.--R8R (talk) 12:28, 4 November 2020 (UTC)

@R8R: a bit much to ask from outsider participants: Thank you for phrasing this eloquently, because it's precisely why I'm generally not too enthusiastic about opening the question to a wide RFC. After all: the general community probably is not at all keenly aware of the situation. Even among chemists some of these issues are pretty obscure. Double sharp (talk) 15:57, 4 November 2020 (UTC)

EdChem

1. Fidelity to what?
2. Presentation is unbalanced / biased – a comment that reactive nonmetals is suspect (IIRC) is clearly advocating for one position over another.
3. Since both options include noble gases, the question is really about the non-metals excluding the noble gases.
4. I understand that halogen non-metals is offered to exclude astatine (and possibly tennessine) but how many who use the PT are going to continue to simply refer to halogens?
5. why is the option of halogens, chalcogens, pnictogens not offered?
6. The question presupposes that none of the metalloids are non-metals. I suspect many readers will have learned the PT with a metal / non-metal boundary and metalloids around it, some as metals with non-metal characteristics, some as non-metals with metallic characteristics. Is there an established consensus for the metalloids to be treated separately from metals and non-metals? If so, I would note this in the preamble or background.

An RfC is meant to offer a simple question for outsiders to consider and offer a comment. The background should neutrally present the arguments / evidence for others to consider in forming a view. Advocacy belongs with comments / views / !votes, etc. The above list points to potential issues that an outsider might wonder about and which thus are worth considering in constructing an RfC. Also, an RfC cannot override what the consensus of RS is... and so should not offer such an option. For example, we wouldn't hold an RfC to decide on metalloids as a separate collection / set if the consensus of literature is that they are; rather, we'd document the RS consensus and (as needed) discuss its implementation. We may hold an RfC, for example, if RS given DUE consideration support two possibilities and we choose which to present and which to discuss as the alternative.

Some of the issues are ones I haven't reached a conclusion with my Wikipedian hat on. As an educator and thinking pedagogically, I can't see the benefit that comes with "halogen non-metals" over "halogens" given the insignificance of astatine. As a chemist, I can see the benefit of precision but wonder if chemists will simply understand when astatine is included / excluded by implication. As Wikipedian, however, as RS are drawing such distinctions I have to wonder about the appropriate inclusion of such terms... but at the potential cost of over-specialising encyclopaedic content and in so doing rendering WP less accessible for non-specialist readers. Not an easy one, either to decide or even to construct an RfC about... but the draft needs some re-drafting, IMO. EdChem (talk) 22:20, 1 November 2020 (UTC)

@EdChem: Thank you very much for your fresh perspective.

In drafting the RFC I aimed to be as concise as possible. There is so much more I could include in the RFC or write in response to your observations but I choose not to, in light of guidance provided to me by other editors to keep one's RFC "short".

1. "Fidelity" means better fidelity in classification science, I suppose. Or there is historical momentum. Since it's inception in 2002, the WP PT has had three nonmetal colour categories over 18 of its 20 years. We changed to two categories in 2018 as almost nobody "liked" other nonmetals.

2. NPOV is very important, and I was wondering how to achieve that. I take your point about saying reactive nonmetals is "problematic" and I added an explanation about why it is regarded as such. Do you have a suggestion for better wording? I'll look at this further.

3. I included the NG so as to put the question into context, and that it was about classifying the nonmetals generally.

4. Yes, many folks who use the PT will continue to simply refer to the halogens just as they refer to the pnictogens and the chalcogens, never mind the cross-cutting metalloids. Bear in mind the WP PT is more of PT showing the left to right progression in metallic to non-metallic character, rather than a groupic table. Also, that the main WP PT shows the group names as well as the colour categories. There is room to show the group names on our WP graphic, but other WP:ELEM editors seem not keen on this option and have argued this will add too much detail. YMMV.

5. The option of chalcogens, halogens, pnictogens is not offered, (a) in order to keep the focus simple and targeted; and (b) since the WP:PT, being a metallicity table, has never shown these as colour categories (except when At was coded as a halogen).

6. It has been known for over 120 years that metalloids have a predominately nonmetallic chemistry (including those sometimes regarded as metals i.e. Ge, As, Sb). Ontologically, anything that is not a metal, is a non-metal. That said, with the emergence of the semiconductor industry in the 1950s, and the development of solid-state electronics from the early 1960s, metalloids came to be regarded as “in-between elements. They are still widely regarded as such. I'm inclined not to add this to the RFC on word count grounds.

A traditional aspect of teaching the periodic table is to contrast the alkali metals with the halogens. This cannot be done with the lede WP table.

As an educator, and pedagogically, the significance of halogen nonmetals is that the halogens are as much subject to the increase in metallic character going down the group, as other groups. Already, iodine is a semiconductor with a band gap of ~1.3 eV, and has a metallic appearance under white light. Indeed, astatine (based on its chemical behaviour) was thought to be a metal when it first synthesised in 1940. There is much on WP that is less accessible for non-specialist readers. I doubt simple periodic trends and a division of the elements into simple categories is one these, including the resulting symmetry (see the Category relationships table). This symmetry can facilitate learning since fewer observations are required to describe the applicable system.

--- Sandbh (talk) 00:42, 2 November 2020 (UTC)

@EdChem: I believe I've now addressed all of your concerns. Sandbh (talk) 08:33, 2 November 2020 (UTC)

Sandbh

@Narky Blert, DePiep, R8R, EdChem, Double sharp, and ComplexRational: I intend to go live with the RFC on Friday 6 Nov, my time (Eastern Australia). Sandbh (talk) 03:42, 3 November 2020 (UTC)

@Sandbh: I hope the issue of the collusion between your proposal and Double sharp's will have been resolved by then, and a way to coordinate the two proposals will have been found.--R8R (talk) 13:45, 4 November 2020 (UTC)

@Sandbh: (1) I presume the RfC text to be centralized will just be Q1 and Q2. (2) Do you want to explicitly request that people not respond to !votes in threaded discussions (3) You said I've asked some chemistry teachers if they use CHONPS. If you'd asked me, I would have said, "I've been using them continuously ever since sperm fertilized egg nine months before I was born. YBG (talk) 08:50, 6 November 2020 (UTC)

@YBG: (1) Yes. To be clear, I intend that the RFC will include everything between the two pairs of double lines. (2) I believe this is covered by the "Survey instructions", namely "Anything beyond a simple !vote for either two categories; or three categories (+ your Table 2 pick/s), should be placed in the "Discussion" sub-thread, following." (3) Yes, quite so. The full question was, "Have any chemistry teachers heard or used this term?" To which one responded, "Yes, I have used CHNOPS for years." Sandbh (talk) 22:14, 6 November 2020 (UTC)

@Sandbh: (2) I agree it is covered, but I'm not sure sufficiently that people will "get" it. But your choice. (3) Right, my joke only worked by eliminating the term "term". YBG (talk) 23:00, 6 November 2020 (UTC)

@YBG: Roger that re (2). I'll look at it. Brevity is everything in an RFC, but. Sandbh (talk) 23:41, 6 November 2020 (UTC)

RFC supporting information

Moderately active nonmetals

• Timm (1950): "Oxygen is a moderately active nonmetal and will combine directly with nearly every other element to form an oxide.
• Gelender at al. (1959): "This oxidation may be accomplished by: (a) The use of suitable oxidizing agents for moderately active nonmetals."
• Perlman (1970): "Between Groups I and VII there are gradations from active metals (Col. I) to less active metals to moderately active nonmetals to volatile nonmetals (halogens Col. VII)."
• Wulfsberg (2000): "Most of the moderately active metals and nonmetals (the electropositive metals and electronegative nonmetals) are reduced from their oxides…using carbon."
• Welcher (2001): "The elements change from active metals to less active metals, to metalloids, to moderately active nonmetals, to very active nonmetals, and to a noble gas."
• Sorokhtin at al. (2007): "Nitrogen is a moderately active element, reacting weakly with natural inorganic compounds."

Shared properties of H, C, N, O, P, S, Se

• They appear sub-metallic (C, P, Se), coloured (S) or colourless (H, N, O), and are brittle if solid. Black P, the most stable form in ambient conditions, is these days easily prepared.
• Being sandwiched between the strongly electronegative halogen nonmetals and the weakly nonmetallic metalloids, their net chemical nature is moderately non-metallic. Hence the term moderately active nonmetals found in the literature.
• Each one has an associated biogeochemical cycle, thus: hydrogen cycle; carbon cycle; nitrogen cycle; oxygen cycle; phosphorus cycle; sulfur cycle; selenium cycle.
• Multiple vertical, horizontal and diagonal relationships
• A proclivity to catenate peaks in this part of the periodic table (for H, see here). Silicon and boron do this too, but they are two of the elements most commonly recognised as metalloids, and are shown as such on the WP periodic table.
• Uses in explosives and combustion; nerve agents; and organocatalysis.
• A capacity to form interstitial and refractory compounds, in light of their relatively small atomic radii and sufficiently low ionization energy values
  

WP:ELEM Protocol (very draft)

As mentioned at WP:ANI here’s a suggested protocol setting out aspirations for the way we do things around here. I've strived to keep the word count as low as possible. Less is more, in my view.

In no particular order, after item 1(   = no change):

These items have been informed (and biased) by my recent experience here and at WP:ANI. Feel free to shoot, salute, amend, suggest or add your own items. --- Sandbh (talk) 01:14, 1 November 2020 (UTC)

@Double sharp, YBG, EdChem, R8R, ComplexRational, and DePiep: per above. Sandbh (talk) 01:21, 1 November 2020 (UTC)

@Sandbh: I'll write my initial comments; I hope to expand and act on them next week.

It is strange that the OR part focuses on talk pages whereas this sort of thing is clearly secondary to what happens in the article space.

The ownership part is very vague and leaves interpretation to the reader.

I wouldn't expect us to "focus on what science says." I'd expect us to focus on what reliable sources say. There's a difference between the two, namely in that the science part is less discouraging from OR on what is truly scientific and source interpretation. I wouldn't expect fuzziness being mentioned in the rule set; this is more specific that what rules suggest.

I fear that "festival of WP:POLICY citing" is too vague a phrase to have any concrete meaning; people will interpret it differently, and some may question it altogether. I don't quite understand what kind of behavior I'd be expected to display upon reading such an instruction.--R8R (talk) 12:39, 1 November 2020 (UTC)

Sandbh, the idea of the instructions (for want of a better word) at the top is to assist in applying the talk page guidelines within the context of the WikiProject. These talk page guidelines apply across WP are cannot be overridden by a local consensus. One area of concerns that I have is that your interpretation of the existing text is inconsistent with my understanding of the intent of the overall guidelines. This could, of course, point to a misinterpretation on either or both of our parts or even simply point to situations where reasonable alternative interpretations are possible. As an example, you appear to see the use of OR to be unrestricted in talk space. I see talk space as directed towards improving article content and OR in aid of that goal is fine... but that this is not a free pass for any OR. In particular, OR that reads as a reason for article space to disregard RS or DUE is problematic in my view. I hope that you would agree with this point in the abstract, putting aside whether this has actually been a problem in any WT:ELEM discussions.

Similarly, when I refer to article content being in line with Science, I mean science as known in the literature based on RS and in line with DUE, presented in an NPOV way, etc... I didn't / don't mean whatever the cutting edge of science would be. I recognise that the presentation of the periodic table as a single object is a difficulty given the variety of tables viewable in books, the small but complicated issues that arise with new elements, the issues of La / Lu, etc. We would have a much easier time writing an article on periodic tableS with pros and cons for each without taking a position on which is the periodic table. I think this is part of the reason that discussions have become complicated. If there was truly a single periodic table about which we were debating superficial presentation, we could just hold an RfC and get a decision where the science does not point at any single answer... but that's not the case. The areas of disagreement reflect scientific issues where reasonable cases can and have been made for different positions.

To me, this implies that relying on the guidance of policy and talk page guidelines that have evolved to address many difficult circumstances in the past. It seems unlikely that the issues here are unprecedented across the 6+ million existing en.WP articles.

It is worth remembering that some of these instructions point at article space behaviour and some at talk page behaviour. WP:BOLD provides advice on article space actions, reverting in article space and talk space has very different meanings, and OR is about an absolute prohibition in the former while allowing some usage in the latter. EdChem (talk) 02:27, 2 November 2020 (UTC)

@EdChem: Thank you; I'll certainly be taking on, and considering your carefully put thoughts. A quick comment. Consistent with WP:IAR, there is no "absolute" prohibition on anything at WP. Sandbh (talk) 04:45, 2 November 2020 (UTC)

Sandbh... in theory, you are correct. In practice, if some hypothetical editor tried to put unambiguous OR into an article, justified by an edit summary acknowledging that it was OR but citing IAR as justification, it would not survive long. The same fate would await IAR-justified edits that clearly ignored policies like NPOV or RS or BLP. An editor repeatedly taking this approach would likely be blocked or banned. I contend that the prohibition of OR in article space, as a matter of policy and practice, is at least close to absolute. If you doubt that, perhaps asking at WT:OR will provide further opinions. EdChem (talk) 11:10, 2 November 2020 (UTC)

Seconded. The essence of WP:IAR is, Do not rigidly apply formal rules if they impede readers' ease of understanding. It does not in any way override our duty as editors to try to ensure that WP contains nothing but accurate well-documented well-established information. Narky Blert (talk) 20:33, 2 November 2020 (UTC)

@EdChem and Narky Blert: I should've quoted WP:IAR, which is derived from WP:5P5, in full: "If a rule prevents you from improving or maintaining Misplaced Pages, ignore it." So it is not the case that anything goes at WP per WP:IAR, per se. It is more subtle than that. So, if e.g. OR, NPOV, RS, or BLP prevents you from improving WP, ignore them, per WP:IAR. Of course, what happens after that is subject to the views of WP editors generally, as is the case with any edit. Sandbh (talk) 21:58, 2 November 2020 (UTC)

Sandbh, perhaps think of the "you" in IAR as less you (singular), a single editor, and more as a collective... that is, IAR applies when the change prevented by a rule is one that a consensus of uninvolved editors would agree is an improvement, justifying ignoring the rule. In my experience, IAR does cause individuals to get into difficulties when what a single person sees as an improvement is seen by many others as unhelpful / detrimental. This topic might be more effectively explored with concrete examples rather than in a theoretical manner and at a meta level, where each perspective has positives and negatives. EdChem (talk) 02:40, 3 November 2020 (UTC)

@EdChem: Thanks. As WP:IAR, as written, refers to "you" (rather than a collective) I'll continue to read it that way. As I understand it, WP:IAR does not mention the need for a "consensus of uninvolved editors" before it can be acted upon (per WP:BOLD). Of course, WP:BRD can be applied thereafter. Sandbh (talk) 03:00, 3 November 2020 (UTC)

@EdChem: Oh my. I just looked at Misplaced Pages:Talk page guidelines and ran head long into a 6,400+ word count extravaganza. Talk about a wall of text.
--- :( Sandbh (talk) 22:20, 2 November 2020 (UTC)

@EdChem and R8R: I feel I may have now addressed and accommodated your comments. How do see the protocol now? Sandbh (talk) 03:32, 3 November 2020 (UTC)

@Sandbh: As long as #8 is there this will never get my support. The whole point is to focus on what the reliable sources say, even if you or anyone else thinks they are all scientifically wrong. Judging by your comments on the Lu sources, calling them unscientific just because they are based on single arguments (which oddly enough never stopped scientists from citing them and oddly enough is not a criticism that has appeared elsewhere), it seems you cannot do that. Oh, not to mention that #9 is also an immediate dealbreaker. We are talking on WP, we should abide by its rules when it comes to not just article-writing, but the necessary discussion that builds consensus for what goes into the articles. Yes, in general policy citing is undue because everyone involved usually has a good grasp on policy. Judging by how EdChem has to keep explaining to you things about WP:IAR which you don't listen to, it seems you don't, which makes it not undue anymore. Oh, not to mention #4 which also is an immediate dealbreaker for me for the exact same reason. And also #6, which rather makes things good only for people who shoot things into articles without trying to get a consensus: a normal policy-abiding Wikipedian who thinks his change may be controversial has to go through discussions, and someone who decides to just put his text into an article has suddenly immunity to reversion because lack of consensus is apparently not a reason to revert. No, I will not accept any of this, because I would like Misplaced Pages to remain Misplaced Pages. Double sharp (talk) 11:53, 4 November 2020 (UTC)

@Sandbh: I do not find that this protocol will aid the development of the project as it stands. I do appreciate the effort put into it but I think that many points need a greater level of precision before we could discuss them because they are very open for different interpretations.

2. "keeping in mind that the purpose of our rules and guidelines is to make the best encyclopedia possible" -- people will inevitably disagree on what this means. Say, there has been disagreement about that between you and me. This phrase will hardly help us resolve the differing views because it's rather vague, and you and I will fill it in differently.

3. "Being sharp, at times, does not constitute incivility" -- I, again, fear that this phrase lacks sufficient substance to make sure it means the same thing to all editors.

5. "Nobody owns any article, template, table, content or domain of knowledge." -- the same comment. What does it mean exactly? Is WP:OWN not enough?

8. I feel my previous concern has not been resolved. We are not supposed to focus on science, we are supposed to focus on reliable sources. Misplaced Pages:Reliable sources is a core policy of the English Misplaced Pages. We can't adopt a guideline that would contravene that. We shouldn't have such a guideline.

9. My concern has not been resolved, either. What is "undue WP:POLICY citing"? Again, you and I differ on what is undue policy citing and what isn't. How is this guideline going to help us?

One thing I agree with is explicitly stating that lack of beforehand consensus is not a sufficient reason to revert someone's bold edit unless there is an established consensus behind the current standing that such a bold edit would contradict.--R8R (talk) 14:12, 4 November 2020 (UTC)

While I applaud the efforts here, I find my self agreeing with R8R's concerns. IMO, many (if not most) of these proposals are problematic. However, I am not sure I agree with the protocol re reverting and R8R's comment on it. I am concerned that #6 could be read as an explicit rejection of WP:BRD, which though not a policy, I have found to be a very helpful guideline. It might be better to scrap this thread entirely. I think the site-wide guidelines are sufficient. YBG (talk) 15:42, 4 November 2020 (UTC)

@YBG: I think the site-wide guidelines are sufficient. +1, thank you. They should be sufficient indeed IMHO, as befits their being site-wide. The problem is that people have to respect them. With the general community understanding trumping whatever one thinks they mean when they disagree, befitting how WP is built on consensus. Double sharp (talk) 15:48, 4 November 2020 (UTC)

@YBG and Double sharp: There is generally no problem in restating policy as long as we don't contradict it. We can have it as a local guideline, too (whether we should, however, is another issue), to put some emphasis on a given policy/guideline if there is a desire to do that. As for reverting without expressing a particular concern with an edit and merely noting lack of beforehand approval, this is actually discouraged, too. WP:BRD: "BRD is not a valid excuse for reverting good-faith efforts to improve a page simply because you don't like the changes. BRD is never a reason for reverting. Unless the reversion is supported by policies, guidelines or common sense, the reversion is not part of BRD cycle."--R8R (talk) 16:08, 4 November 2020 (UTC)

When a GF bold edit replaces long-standing text with alternate text that is controversial, I think a revert followed a discussion is the right approach under these circumstances. I am concerned that #6 could appear to contradict this. But even if it does not, I still think it would be best to stick to site-wide norms and augment them only when there is an overwhelming agreement among project participants. By overwhelming, I do not mean unanimous. If everyone in the project but me agrees, that is clearly overwhelming. IMO, the most likely (and most fruitful) area for project-specific guidelines would be if some project-specific concern is unmentioned or ambiguous in the WP guidelines. But even that can be overcome, see, for example, WP:ALUM. YBG (talk) 16:47, 4 November 2020 (UTC)

@YBG: if an edit is controversial and you can identify in what specific ways it is controversial (other than simply being not what it used to be), then it's fine to call for a discussion as I see it and I don't see a problem with that. Each individual editor should recognize their opinion is not paramount, both the one who sees a potential problem (therefore admitting other editors may not share the concern) and the original editor (admitting the stated concern is probably worth raising).

The whole reason why I think we could have our own guidelines (that would supplement or even simply restate, rather than contradict, the site-wide guidelines) is this. While the site-wide guidelines are supposed to work and there's that, as we have seen throughout this year, they sometimes don't. Do we want to do anything about it? One response could be, we should do nothing, the site-wide guarantees are already perfect or as close to that as it gets. Unfortunately, this response would do nothing to help solve the problem. Another response could be, we could bring the behavior of an editor who violates the guidelines under the spotlight of ANI. I believe there is no real desire to have this as the final ending, either. So what else could it be? The thing that comes to my mind is having our own "gentlemen's agreement," or call it whatever you will. If we were to discuss what kind of behavior we wanted to see from other editors and what standard of behavior we were willing to stand by, this could have a positive impact on our future relations within the project. Even if the agreements themselves don't end up being all that fancy and instead add precisely nothing to the existing guidelines, the very process of negotiating what we particularly want other editors to do could help us a lot, because such a process could help point out how grievances are born and what could be done in order for this not to happen. The possibility to point out the results of such a discussion in the future if someone does violate the agreement, willingly or not, is also important.

@YBG, Double sharp, DePiep, Sandbh, and EdChem: if there are other ideas that could help us not end up in conflicts in the future, I'd like to hear it very much, and I'm sure others would like to hear it, too. There has been a number of conflicts this year. Do we want to help ourselves to stop the count for this year, and ideally forever, at whatever value it is right now, or should we do nothing and see if the problem resolves by itself? If we do want to be more active and help ourselves, what could such help be like?--R8R (talk) 13:21, 8 November 2020 (UTC)

@R8R: Another response could be, we could bring the behavior of an editor who violates the guidelines under the spotlight of ANI. I believe there is no real desire to have this as the final ending, either – indeed, I do not like having to go to this ending, but I always felt it should be on the table. If the general community interpretations of the guidelines are perpetually rejected in favour of one's own idiosyncratic ones, and despite lots of suggestions nothing changes – then yes, it becomes my desired ending because nothing else will work. If someone wants to stay on this site – follow the site guidelines. Anyone may write whatever he or she wants elsewhere where the guidelines are different. Double sharp (talk) 13:58, 8 November 2020 (UTC)

@Double sharp: I agree with what you wrote, but it doesn't really answer my question. I am looking first and foremost for a way to facilitate abidance by the rules, rather than for a way to alter them. I'm not looking for a way to get ANI off the table entirely, either, though I take it we should try our best not to end up there; only if we must. This was the sort of suggestion I got when I started an ANI, and I've internalized it, it makes perfect sense to me. What can we do in order to be able to say, "we've tried everything, and as much pain as this brings, there is no other way, because everything else has been tried, and I commend the latter statement"? "Follow the site guidelines": how do we stimulate that? I've proposed a suggestion: we talk it all through and all once again explicitly commit not to do what might disappoint others provided the agreement does not contradict in the general framework of Misplaced Pages policies and guidelines. To me, it looks like a good thing however you look at it: it should allow you to state your concerns with other editors, and allow other editors to hear you and tell you what they don't like about your behavior; it doesn't take ANI entirely off the table but also discourages you from pushing for it unless you absolutely must. Don't you think this would be the most collaborative and reasonable thing we could do, and that it would be better to try it? If you think it wouldn't help, why not?--R8R (talk) 14:51, 8 November 2020 (UTC)

@R8R:. Best step would be to improve discussion quality. When contributing, engage & respond, not soapboxing one-way talking. Stay on topic; one-topic-one-place; and be brief (long posts indicate immature thoughts). Keep threads & sideroutes organised. All as a collective (common) effort. Also, discussions are intended to develop into a common result. That implies: digest opposing arguments.

Whether we work by wiki-wide guidelines or local ones, this talkpage attitude is required. IOW, if such attitude is absent, any discussion will run into the sand or in the long grass, and makes frustrations easier to enter. Personally, I can say that a well-performed thread is easy to be loyal to. All this was very common before 2020, so it's not new to us. -DePiep (talk) 16:06, 8 November 2020 (UTC)

@Sandbh: Not to mention that even if we were supposed to focus on science, that huge argument from the early part of the year should have made it abundantly clear that what you think is correct science is assuredly not guaranteed to match what other editors think is correct science. Double sharp (talk) 15:21, 4 November 2020 (UTC)

I have another concern about adding project-specific guidelines in a small project such as ours. Whenever you have guidelines, there is the possibility of differing interpretations. If a dispute over project guidelines arises, our ability to find uninvolved project members to mediate is severely limited. But if we have a project disagreement on the interpretation of some site-wide guideline, it is much more likely that we can find uninvolved mediators who can resolve the issue. Even with the ugliness of our project's recent experience at ANI, I still prefer that forum to a free-for-all just amongst ourselves. YBG (talk) 16:47, 4 November 2020 (UTC)

@YBG: +1 Double sharp (talk) 17:13, 4 November 2020 (UTC)

• DePiep says: No way. No reason or need to make separate guidelines for WP:ELEMENTS. Why should an editor have to sign up to any extra set? The issue is: the already available guidelines are not being respected. And why redefining "assume GF", "no PA", "no OWN"? duh.

I am not very familiar with the source issues at ELEM, but I am sure e.g. EdChem (skipping Double sharp here) recently has added good guidance on handling sources (again, without requirement for new guidelines).

TL;DR: No, no separate guidelines. -DePiep (talk) 23:15, 7 November 2020 (UTC)

@DePiep: +1. If it is consistent with pan-WP guidelines, there is no need to say it again, and if it is not, then one should not create an enclave on WP where pan-WP guidelines don't apply. Double sharp (talk) 23:28, 7 November 2020 (UTC)

Sit rep comment by Sandbh: I haven't recently commented or edited here pending the outcome of ANI #3. I may do so if I have some spare time. Sandbh (talk) 05:03, 9 November 2020 (UTC)

Eric Scerri YouTube workshop

This workshop (1h 41m) was conducted remotely via Zoom. 150+ people from 16 countries registered. It was organized by the American Chemical Society in association with Yale University.

Topics discussed by Eric include:

• teaching 3d-4s orbitals
• Madelung Rule
• differentiating electrons
• Group 3
• HFSS (half-filled sub-shells).

--- Sandbh (talk) 01:27, 5 November 2020 (UTC)

Ten most influential chemists today

Here. --- Sandbh (talk) 21:49, 5 November 2020 (UTC)

IUPAC Group 3 project update

​​ From Eric Scerri: "Before delivering a report I will be publishing an article in Chemistry International which discusses our preliminary conclusions and will be asking for comments and feedback. I'm still writing the article." "By all means share this update." --- Sandbh (talk) 09:07, 8 November 2020 (UTC)

@Sandbh: Thank you, this is useful information to keep in the back of our heads. We can start to consider it for content discussions when his article appears – which I hope happens soon. Double sharp (talk) 19:11, 9 November 2020 (UTC)

On the inevitable misunderstandings that arise from giving individual elements single category colourings

Textbook example. Double sharp (talk) 19:10, 9 November 2020 (UTC)

Isn't the misunderstanding in the "typical" there? (is 'misunderstanding' the right word here btw?). DePiep (talk) 19:30, 9 November 2020 (UTC)

@DePiep: Ah, maybe I should have made it clearer. In my view the misunderstanding was that the IP editor thought the statement that boron was a typical "non-metal" was an "error" and replaced "non-metal" with "metalloid". In actual fact, this is hardly true; there is hardly a consensus in the literature as to which elements are nonmetals, or even as to whether metalloids as a category should exist at all. So it is not an "error": boron can certainly be called a nonmetal and some sources even do. But when you see boron, coloured in on Misplaced Pages as just a "metalloid", called only that in {{infobox boron}}, called only that in Period 2 element, called only that in List of chemical elements; then I would be massively surprised if people did not start thinking that that was somehow a correct classification and that anything else is an "error". It is the most natural conclusion to get from what we show and it is also just wrong. That is my quarrel with colouring categories and it will remain forever unless the literature suddenly starts having a consensus on such things. (I do not feel that it should in the first place, but the important thing is whether it does or not, not whether we feel it should or not.)

Such a problem impacts pretty much all categories. Is it "lanthanides" or "lanthanoids"? Do actinides/actinoids include Ac, or not? Do transition metals include group 12, or not? Are they called post-transition metals or poor metals or something else? Are the metals even split the WP way, or perhaps by class A vs class B behaviour or perhaps by electronegativity? Are we splitting nonmetals by groups or something else? Do halogens necessarily include At? Ts? Is Og a noble gas by default, or does its chemistry have to be confirmed first? Are Be and Mg alkaline earth metals? When 119 and 120 are discovered, do they automatically become alkali and alkaline earth metals, or not? Are rare earth metals used? Can categories overlap? No consensus exists for any of this in the literature, so why are we trying to decide ourselves and fly in the face of WP:NPOV?

I am of the opinion now that the colouring of our PT in the first place by our much-admired pioneers at this project was the "original sin" here. If it had not been instituted so early, then I suspect it would never have gotten up due to WP:OR concerns. Now instead the uphill battle is to dislodge it. And this is coming from someone who actually does feel personally that it's an easy task to define metals and nonmetals and make it clear which elements are which, and only does not support doing it for WP because there's no agreement in the literature for how to do it.

Well, hopefully that explains things better. ^_^ Double sharp (talk) 20:31, 9 November 2020 (UTC)

TL;DRall. 1. Not just the infobox boron; the infobox facts 'must' be pulled from the article body text. You say boron is not considered metalloid "at all"? 2. Also in Lists_of_metalloids (166/194=86%) i.e., ~not enwiki/OR. 3. If we were to drop the nine categories, there still would be the super-three categories metal-metalloid-nonmetal. Little attention here on enwiki, but major -- while retaining catergory-border-elements issues I agree. 4. There is also the ??wiki option, graphically nice too: (todo: find two-color-thatching PT, I saw recently). 5. Please don't say "coloring metalloid", it's "classifying metalloid" -- colors just follow. 6. I see your campaign to get rid of cat/colors, but in this we still could get the (metalloid) facts right. -DePiep (talk) 21:07, 9 November 2020 (UTC)

@DePiep: The lists of metalloids article only lists sources that consider "metalloids" to be a separate class from metals and nonmetals. Not all do that. I recall User:Droog Andrey saying something about most Russian textbooks not doing that. Those who consider there to be only metals and nonmetals disagree as to which elements are which. Those who consider there to be metals, nonmetals, and metalloids also degree as to which elements are which. So those super-three categories are actually just as as ill-defined as the nine. To mention them? Sure, I'm fine with that and would do it myself. To specifically colour things in so that it looks like their boundaries are clear in the literature, not fuzzy as they really are? I'm not fine with that.

I guess you mean the dewiki option. The problem is that for many elements in the p block you would need not just two but at least three colours among what we currently have (is Se a metal, a nonmetal, or metalloid? you can find sources saying each). Not to mention that our categories do not at all exhaust the categories that have been in the literature. Like I keep saying: where oh where are the pnictogens and chalcogens, IUPAC-approved, even (whereas metalloids are not IUPAC-approved)? Add that and we instantly bump Se up to four. Add in all the splittings of the nonmetals Sandbh has been collecting for his proposed RFC and we can bump it up probably all the way to a dozen. I do not think this is in any way a sustainable solution.

Meanwhile the astronomy editors have come up with an easy solution. Look for example at 90482 Orcus. Well, it is another minor planet, it belongs to many categories. The astronomers have not sought a taxonomy such that each minor planet only appears in one category, just like the chemists have not. So the astronomy editors have, sensibly enough, not tried to create something like that. Under "Minor planet category" we read "TNO  · plutino  possible dwarf planet " with all possible categories in sources listed. And all three are mentioned in the article body text (indeed, in the lede even).

That's what I would like. Categories (which will quite possibly have to be renamed also; where is the source for "category" with the WP meaning?) – as many as you like as in the literature, they can go in the infobox. Antimony can be listed as "metalloid (most common), sometimes metal or nonmetal · pnictogen · post-transition metal (if considered a metal)" and so on and so on. Gold can be listed as "transition metal OR (rarely) post-transition metal · noble metal · platinum group metal · coinage metal". Lutetium can be listed as "transition metal OR inner transition metal · rare earth metal · lanthanoid (lanthanide)". Astatine can be listed as "metal OR metalloid OR nonmetal · halogen? · post-transition metal (if considered a metal)". And all of these different categories can be mentioned in the article. I just do not want this rich situation to be distorted into one colour for each element and just one category. Out of a cherry-picked nine when there are many more in the literature. Especially when the nine are trying to be jointly exhaustive and mutually exclusive and even then fail at doing it (what are the heavier members of group 3? they're TMs but the tables don't make it clear). And the nine being grouped into three supercategories (metal/metalloid/nonmetal), when many sources in the literature (particularly the Russian ones) give only two (metal/nonmetal). In my opinion, our current PT colouring is an OR/SYNTH/UNDUE festival that should stop. Double sharp (talk) 22:47, 9 November 2020 (UTC)

This thread merits further consideration.

On the status of B there is this article (by me), Which elements are metalloids? with 29 GS citations. It appeared in the Journal of Chemical Education and concluded that B is one of the six elements that are commonly recognised in the literature as metalloids. There has been no dissent across the 29 citations, as to my conclusion.

More to follow. Sandbh (talk) 22:28, 9 November 2020 (UTC)

We note in our periodic table article that, "Different authors may use different categorisation schema depending on the properties of interest." To this end. I've added an other categories section with a w/link to our article on names for sets of elements.

I know of no RS supporting the premise of this thread, i.e. "the inevitable misunderstandings that arise from giving individual elements single category colourings".

None of the authors of the following colour category PTs appear to think this is a problem:

1. the Encyclopaedia Britannic PT, which predates the WP PT, features nine colour categories
2. the most popular Google PT, which postdates the WP PT, features nine colour categories
3. Gonick & Criddle, in The Cartoon Guide to Chemistry (2005, p. 38) refer the reader to the LANL PT which they describe as "a wonderfully information-rich" PT. This has ten colour categories.
4. The ACS PT has ten colour categories.
5. The RSC PT has eight main group colour categories; one TM colour category; and one each for the Ln and An.
6. The World Book encyclopaedia of science: Chemistry today (1986, p. 23) has a PT with 20 colour categories. In the text, they "group: the following elements: H; AM, AEM; coinage metals; AEM; group 12; group 13; C; Si–Pb; Ti–Ni; Zr–Tc and Hf–Re; PGM; N; P–Bi; O; S–Po; halogens; rare gases; Sc group and the Ln; An.

Since the days of the classical elements of the ancients, humanity has a proclivity to categorise things. Categories demand explanations which may lead to new or refined categories which demand explanations etc—that sort of iterative process is at the heart of science

We strive to cover significant viewpoints in the literature; that would encompass: AE,* AEM,* Ln, An; TM; metalloids, halogens,* noble gases* (* = IUPAC approved). That leaves the group 12–17 metals and the group 1 to 16 nonmetals. WP:ELEM chose PTM for the group 12−17 metals; WP:ELEM chose other nonmetals (2003-2013), and then poly/diatomic metals (2013-2018), and reactive nonmetals in 2018. WP:OR has been around, in one form or another, since December 2003; I can't recall WP:OR concerns having been raised during this time.

Categories are rarely sharp (Jones 2010, p. 170; Atkins 2013, p. 3). There are all sorts of fuzzy boundaries in chemistry https://www.newscientist.com/article/mg21128234-100-redefining-hydrogen-bonds-the-givers-of-life/]. Needless disputes arise wrt fuzzy boundaries

--- Sandbh (talk) 03:55, 10 November 2020 (UTC)

@Sandbh: Of course they do not think it is a problem. They are giving their own viewpoints. We on Misplaced Pages, on the other hand, are supposed to reflect the situation in the literature, in which no single viewpoint predominates. The disagreement in categorisation between the colour-category PTs you show speaks for itself. And I see there's more synthesis in your rationale with yet another reference to Jones, which as I mentioned is a source primarily about the classification of Pluto and does not mention classifying chemical elements at all. Double sharp (talk) 08:38, 10 November 2020 (UTC)

@Double sharp: Misplaced Pages is no different than any other encyclopedia. Those other encyclopaedias are not giving their own viewpoints; rather, as encyclopaedias, they are giving their viewpoints of what the literature says i.e. an encyclopaedic overview of each topic. This is what we do, too. Of course there will be differences in coverage given the involvement of different editors.

Jones was discussing a principle of classification science. Such a principle applies across domains of science, including chemistry and e.g. biology. I cited Jones in my peer-reviewed articles on organising the metals and nonmetals and the location and composition of group 3 . Jones will be cited again in a forthcoming peer reviewed article: Cao C, Vernon RE, Schwarz WEH, & Li J, Chemistry in periodic tables. Frontiers in Chemistry. . Sandbh (talk) 11:18, 10 November 2020 (UTC)

@Sandbh: So why is it that four of the six sources you give are not encyclopaedias? And what does it matter when it's quite easy to demonstrate by looking at other sources that what even the two encyclopaedia sources give is not a good reflexion of what the literature as a whole agrees on (because there is no such thing)? Double sharp (talk) 11:26, 10 November 2020 (UTC)

@Double sharp: I guess, I don’t know for sure, that we strive to reflect the consensus in the literature, noting consensus does not require unanimity. With the metalloids for example, the consensus in the literature is that B, Si, Ge, As, Sb, Te are the six elements most commonly recognised as metalloids. That said, we note the variations at the boundaries in the metalloid article.

There is an essay WP:NOTSYNTH which touches on aspects of this. For example:

• "This essay is intended to help explain the spirit of that policy. In particular, this essay is intended to oppose taking an excessively strict interpretation of the policy in many cases. After all, Misplaced Pages does not have firm rules."
• "SYNTH is not a rigid rule. Misplaced Pages doesn't have them, supposedly. But if a policy gets enforced zealously, it can be hard to tell the difference. The solution is to not enforce policies zealously. Never use a policy in such a way that the net effect will be to stop people from improving an article."
• "What matters is that all material in Misplaced Pages is verifiable, not that it's actually verified. By this we mean that it is important that a suitable reliable source that supports this material has been published in the real world, not that someone has gotten around to typing up a specific bibliographic citation in the article.
• ”Citations are not an end in themselves. If there's a statement for which no source is cited, that's normally ok, as with the example on Misplaced Pages:No original research: "Paris is the capital of France" needs no source because no one is likely to object to it, but we know that sources for it exist. Likewise with very many unsourced statements, regardless of whether they could be deduced from sourced statements in the same article, we know the sources exist."

While these extracts don’t directly address your concerns I suggest they illustrate the principle/s involved.

--- Sandbh (talk) 22:25, 10 November 2020 (UTC)

@Sandbh: (1) That's only among the sources that do consider metalloids to be separate from metals and nonmetals. (2) While maybe among those sources those six are common inclusions, already there is fuzziness with the next tier of Po and At with half saying yes and half saying no. So where exactly is the supposed consensus in the literature for the classification of those two? (3) The issue with application of policy and rigidity (that statement is already going to the WP:IAR) has been discussed endlessly both here and at the WP:ANI thread about you.

The problem with those words "improving an article" is that people will disagree endlessly about what is and what is not an improvement. Frankly I am astonished that I keep having to point out that different editors may have legitimate different perspectives on what constitutes an improvement to the article, when we spent the better part of the year arguing over which presentation of group 3 would improve WP. That's precisely why we have such a thing as WP:CONSENSUS and other policies. It takes consensus to determine if WP:IAR applies, not just one editor saying so. You've stated your case, I've stated mine, now the important thing is how many are persuaded and how policy-compliant the arguments are (of course, "colours because WP:ILIKEIT" or "no colours because WP:IDONTLIKEIT" will get nowhere, for example). And in practice, if WP:IAR is being applied against really core policies, such as WP:NPOV as I see here, then discussion with User:EdChem and others through all these ANI threads strongly suggests to me that it will get nowhere. Double sharp (talk) 22:36, 10 November 2020 (UTC)

@Double sharp: On the ubiquity of metalloids in the literature I turn to four sources. The first is IUPAC and its three unsuccessful attempts to recommend against the use of the term metalloid to refer to the in-between elements. All that happened is that the prevalence of the use of the term metalloid, in the literature, skyrocketed. The other wisdom is that of the big three, namely C&W, G&E, and Wiberg, all of whom recognise metalloids.

The consensus in the literature is that the elements most commonly recognised as metalloids are the usual six. For Po and At we know from the lists of metalloids, that they appear about half as often. I've been watching the recent literature, and it seems to me that their appearance frequencies as metalloids are reducing, following the publication of my article on Which elements are metalloids? in JChemEd, this very article arising out of the chaos that use to be our metalloid article, now TFA.

I agree with you wrt the rest of what you said, with one caveat. Consistent with WP:BOLD, an editor can edit and invoke WP:IAR. They're then subject to BRD, of course. This may or may not resolve the issue, and may subsequently result in the need to establish consensus on whether the invocation of WP:IAR was (in which the case edit stands) or was not reasonable (in which case the R stands). Sandbh (talk) 00:24, 11 November 2020 (UTC)

@Sandbh: So, please tell me exactly how consistent that big three (there are other books around of course) are on exactly which elements are metalloids. I am pretty sure G&E was not even internally consistent on it the last time I checked. And please tell me exactly what you think might be a reasonable consensus categorisation of polonium and astatine in this scheme. I really wonder what could possibly be one when there is literally pretty much a half-for and half-against for the question "are they metalloids". And please tell me how much you think non-English sources should count; I recall from conversation with User:Droog Andrey that in Russian sources it is not common to use metalloids. After all, IUPAC is international, isn't it? Incidentally if we take that seriously, alkaline earth metals becomes seriously more iffy because we then have to consider Japanese and Russian sources where Be and Mg are way more often excluded than they are in English! ^_^

P.S. Why is it that the recent literature is important when it comes to pushing Po and At out of the metalloids box, but when opposing a shift of group 3 to Sc-Y-Lu the 4:1:1 figure keeps getting trotted out based on textbooks all the way back to the 1970s? And exactly how much are those frequencies for Po and At reducing? And why is such a reduction that happened after one of your articles got published relevant here, but we heard nary a word from you at Misplaced Pages talk:WikiProject Elements#Details of Sandbh's opinion and ensuing thread about the reduction of frequency of Sc-Y-La from over a 3/4 supermajority all the way to just losing a majority since Jensen's 1982 article (and those of many others) was published? And how do you know it had something to do with your article when there was in 2010 also another one promoting the idea that Po and At are not metalloids? Did some source say so, like Scerri said about Jensen's article being an important one in the history of Sc-Y-Lu promotion? Double sharp (talk) 00:30, 11 November 2020 (UTC)

@Double sharp: We talked about G&E, and C&W if I recall right, about their views on metalloids. I don't know where that thread is. For polonium, as far as we know, it has the band structure of a fully fledged metal, and does not exist in a semiconducting form. We also know that it relatively easily forms a cation in acidic solution. Smells like a metal to me. Astatine has been predicted to be a fully fledged metal per Andreas Hermann, Roald Hoffmann, and N. W. Ashcroft, now with 35 citations and no dissent. When it was synthesised in 1940 its discoverers considered it to be a metal. Smells like a metal to me.

This is the the English WP, so I'd ordinarily expect English sources to have priority.

The Russian PT includes metalloids.

My comment about more recent sources wrt to Po and At was an observation that, with 30 citations, my article on metalloids seems to have been noticed and recognised as somewhat authoritative. (I could be deluding myself of course, with my perceptual filters. I try to bear this in mind.) Compared to the elements commonly recognised as metalloids, Po and At never had a chance anyway. The Lu option remains well outnumbered by La, as R8R has noticed. In both cases we note these runners-up in the respective articles.

I corresponded with Stephen Hawkes, the author of that 2010 article on Po and At, before he died. He was a thorough gentlemen. Unfortunately his article garnered ten times fewer citations than mine, and had a very narrow scope. Whereas mine was comprehensive and relied on the lists of metalloids, with its sample size of 194; the "gold standard" as YBG put it. I cited Hawkes.

To my knowledge, no one has said anything about my article on metalloids being e.g. "important" aside from it being cited 30 times.

--- Sandbh (talk) 05:04, 11 November 2020 (UTC)

An article on the use of colour in periodic tables: . Sandbh (talk) 10:41, 10 November 2020 (UTC)

I have never disputed that colours are often used, and often for categories. It is just that there is no standardisation whatsoever in the literature as to what colours are used and what categories they are used for. Double sharp (talk) 11:19, 10 November 2020 (UTC)

A related article: Looking for an order of things: Textbooks and chemical classifications in nineteenth century France . Sandbh (talk) 04:37, 11 November 2020 (UTC)

@Double sharp: I want to address some questions you raised earlier:

1. Is it "lanthanides" or "lanthanoids"?
IUPAC recommends the latter; my impression is that lanthanoids is more popular in the literature including as informed by the ngrams.

2. Do actinides/actinoids include Ac, or not?
When the Ln were originally dubbed thus, it did not include La, since the intended meaning was "like" La. Over time the terms lanthanide and lanthanoid seem to have suffered scope creep, so that they know include La. Certainly that is the way IUPAC interprets it. By analogy therefore Ac is included; ditto IUPAC.

3. Do transition metals include group 12, or not?
It seems to be about 50/50. Even IUPAC recognises something along this line.

4. Are they called post-transition metals or poor metals or something else?
PTM seems to be the most popular term, judging from the literature and ngrams.

5. Are the metals even split the WP way, or perhaps by class A vs class B behaviour or perhaps by electronegativity?
The WP way seems to be popular, as a general way of splitting the metals. The stand out spit seems to be between the inner and outer transition metals. All that's left after that is the AM, and AEM, and frontier metals.

6. Are we splitting nonmetals by groups or something else?
Historically, both i.e. other nonmetals; halogens; noble gases; then polyatomic/diatomic/noble (monatomic); then reactive nonmetals/noble gases. We do the same with the metals.

7. Do halogens necessarily include At? Ts?
IUPAC recognises At as a halogen. It has made no ruling about Ts. The halogens are comprised of four nonmetals and one metal; so to are e.g. the chalcogens comprised of two nonmetals, two metalloids, and one metal.

8. Is Og a noble gas by default, or does its chemistry have to be confirmed first?
IUPAC has made no ruling. The feeling in the literature, as we mention in out organneson article, is that Og is not expected to be a noble gas. It's too soon to call.

9. Are Be and Mg alkaline earth metals?
The consensus in the literature is that they are, even though Be is amphoteric rather than alkaline, and Mg was able to be isolated from its oxide in impure form, via the heating technology of the day, even though 'earth' referred to oxides from which the metal could not be isolated.

10. When 119 and 120 are discovered, do they automatically become alkali and alkaline earth metals, or not?
By default, they probably will be referred to as such, at least at first.

11. Are rare earth metals used?
We don't although EB do. REM seem to have a much greater profile in popular media so WP is arguably out of touch in that regard.

12. Can categories overlap?
They usually do, especially given the fuzzy nature of chemistry.

13. No consensus exists for any of this in the literature, so why are we trying to decide ourselves and fly in the face of WP:NPOV?

Consensus (majority opinion, not unanimity) appears to exist for all of these things in the literature. On Og we tread cautiously and show it as unknown properties; presumably we will do the same with 119, 120. Encyclopedia Britannica, the World Book Encyclopedia, RSC, ACS, and LANL take similar approaches, allowing for the fuzziness of chemistry, which we acknowledge in our periodic table article. So too does the most popular online PT itself modelled after WP.

@Sandbh: Consensus is not unanimity, but for it to be the only view presented it must be clear dominance, which by your sources in your previous comments clearly does not exist. Even the table you call "modelled after WP" doesn't exactly match WP: for one thing, when you expand it to a wide table it shows Sc-Y-Lu, and for another thing, it considers group 12 to be transition metals. Otherwise, you've got to reflect all major POV to avoid WP:UNDUE. Which a single colouring will never be able to do. And of course Q6 fails to answer the question, which is about the literature, not what WP made the call to do as it shouldn't have. Oh, and if you think categories can overlap (Q12), then why do you not propose and not point to a single category scheme that reflects this?

P.S. And now "frontier metals" is presented without comment in these answers. Looking at Post-transition metal reveals that this is a term from your own journal article. I really wonder who else will understand it without further explanation. I am glad that it is just being mentioned and not promoted, but do we have to cloud the issue when the primary thing is what goes into the articles, and not everyone is aware of the zillion category names for this approximate set of elements? Double sharp (talk) 00:21, 11 November 2020 (UTC)

@Double sharp: Our PT represents a form of words in graphical form. If a reader, cookie-cutter stye, chooses to focus on those words alone, absent of their context, that is their choice. We note the otherwise missing context i.e. the fuzziness of the categories in the periodic table article. I've suggested adding a small note to the graphic to this end and have not done so, due to opposition expressed here. I'll draft an RFC about this, and post it to the periodic table talk page. On Q6, WP:ELEM chose those spilts, IGF, via consensus, on the basis of our understanding of the literature, as did the founders of the WP colour category table.

I've proposed overlapping categories for the WP PT, only to meet staunch resistance from colleague here. I recall you even pointed out one of these tables on another of the WP's, the German one if I recall right?

I looked at the 149, by my count, non-English WPs. I found three showing just metal-metalloid-nonmetal; and two block-only tables. So 96%+ show colour categories, such as we do.

Cool tables:

• Arabian(?), with its inclusion of block-only icon.
• French table with something similar;
• German, with its hybrid colourings of Ge, Sb, Se, and At.

I casually mentioned frontier metals in passing, as a way of referring to the metals that occupy "frontier territory: abutting the metalloids. The term itself comes from a peer-reviewed open-access article in the literature (that I wrote), now with 5,400+ access. As the PTM article notes, the name frontier metal is adapted from Russell and Lee, who wrote that, "…bismuth and group 16 element polonium are generally considered to be metals, although they occupy 'frontier territory' on the periodic table, adjacent to the nonmetals.". --- Sandbh (talk) 03:55, 11 November 2020 (UTC)

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