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| Radium=Ra and is the 6th element in group 2 of the periodic table. It has a atomic mas of 88 | |||
| {{about|the chemical element}} | |||
| {{Use dmy dates|date=April 2014}} | |||
| {{infobox radium}} | |||
| '''Radium''' is a ] with symbol '''Ra''' and ] 88. It is the sixth element in ] of the ], also known as the ]s. Pure radium is silvery-white, but it readily combines with nitrogen (rather than oxygen) on exposure to air, forming a black surface layer of radium nitride (Ra<sub>3</sub>N<sub>2</sub>). All isotopes of radium are highly ], with the most stable ] being ], which has a ] of 1600 years and ] into ] gas (specifically the isotope ]). When radium decays, ] is a product, which can excite ] chemicals and cause ]. | |||
| Radium, in the form of ], was ] by ] and ] in 1898. They extracted the radium compound from ] and published the discovery at the ] five days later. Radium was isolated in its ]lic state by Marie Curie and ] through the ] of radium chloride in 1911.<ref>{{Cite web|url=http://www.rsc.org/periodic-table/element/88/radium|title=|last=|first=|date=|website=|publisher=|access-date=}}</ref> | |||
| In nature, radium is found in ] and (to a lesser extent) ] ores in trace amounts as small as a seventh of a gram per ton of ]. Radium is not necessary for living organisms, and adverse health effects are likely when it is incorporated into biochemical processes because of its radioactivity and chemical reactivity. Currently, other than its use in ], radium has no commercial applications; formerly, it was used as a radioactive source for ] devices and also in ] for its supposed curative powers. Today, these former applications are no longer in vogue because radium's toxicity has since become known, and less dangerous isotopes are used instead in radioluminescent devices. | |||
| ==Characteristics== | |||
| Radium is the heaviest known ] and is the only ] member of its group. Its physical and chemical properties most closely resemble its lighter ] ]. | |||
| ===Physical=== | |||
| Pure radium is a ] silvery-white metal, although its lighter congeners ], ], and ] have a slight yellow tint.<ref name=Greenwood112>Greenwood and Earnshaw, p. 112</ref> Its color rapidly vanishes in air, yielding a black layer of ] (Ra<sub>3</sub>N<sub>2</sub>).<ref name=k4>Kirby et al., p. 4</ref> Its ] is either {{convert|700|°C}} or {{convert|960|°C}}{{efn|Both values are encountered in sources and there is no agreement among scientists as to the true value of the melting point of radium.}} and its ] is {{convert|1737|°C}}. Both of these values are slightly lower than those of barium, confirming ]s down the group 2 elements.<ref name="Lide2004">{{cite book|last = Lide |first= D. R. |title = CRC Handbook of Chemistry and Physics |edition = 84th |location = Boca Raton (FL) |publisher = CRC Press |date = 2004 |isbn = 978-0-8493-0484-2}}</ref> Like barium and the ]s, radium crystallizes in the ] structure at ]: the radium–radium bond distance is 514.8 ]s.<ref>{{cite journal | last1 = Weigel | first1 = F. | last2 = Trinkl | first2 = A. | year = 1968 | title = Zur Kristallchemie des Radiums| doi = 10.1524/ract.1968.10.12.78 | journal = Radiochim. Acta | volume = 10 | issue = | page = 78 }}</ref> Radium has a density of 5.5 g/cm<sup>3</sup>, higher than that of barium, again confirming periodic trends; the radium-barium density ratio is comparable to the radium-barium atomic mass ratio,<ref name=Young>{{cite book | url = https://books.google.com/books?id=F2HVYh6wLBcC&pg=PA85 | page = 85 | chapter =Radium|author=Young, David A. |title=Phase Diagrams of the Elements|publisher=University of California Press|date=1991|isbn=0-520-91148-2}}</ref> due to the two elements' similar crystal structures.<ref name=Young/><ref>. uni-bielefeld.de.</ref><!--books.google.com/books?id=QsgmAAAAMAAJ&q="melting+point+of+radium"&dq="melting+point+of+radium"&hl=de&sa=X&ei=8j_iT72ZAYfOsgb-r91v&ved=0CD4Q6AEwAg books.google.com/books?id=1hNSAAAAMAAJ&q="melting+point+of+radium"&dq="melting+point+of+radium"&hl=de&sa=X&ei=8j_iT72ZAYfOsgb-r91v&ved=0CEgQ6AEwBA--> | |||
| ===Chemical=== | |||
| Radium, like barium, is a highly ] metal and always exhibits its group oxidation state of +2.<ref name=k4/> It forms the colorless Ra<sup>2+</sup> ] in ], which is highly ] and does not form ] readily.<ref name=k4/> Most radium compounds are therefore simple ] compounds,<ref name=k4/> though participation from the 6s and 6p electrons (in addition to the valence 7s electrons) is expected due to ] and would enhance the ] character of radium compounds such as Ra]<sub>2</sub> and Ra]<sub>2</sub>.<ref name=Thayer>{{cite journal |last1=Thayer |first1=John S. |title=Relativistic Effects and the Chemistry of the Heavier Main Group Elements |year=2010 |page=81 |doi=10.1007/978-1-4020-9975-5_2}}</ref> For this reason, the ] for the half-reaction Ra<sup>2+</sup> (aq) + 2e<sup>−</sup> → Ra (s) is −2.916 ], even slightly lower than the value −2.92 V for barium, whereas the values had previously smoothly increased down the group (Ca: −2.84 V; Sr: −2.89 V; Ba: −2.92 V).<ref name=Greenwood111>Greenwood and Earnshaw, p. 111</ref> The values for barium and radium are almost exactly the same as those of the heavier alkali metals ], ], and ].<ref name=Greenwood111/> | |||
| Solid radium compounds are white as radium ions provide no specific coloring, but they gradually turn yellow and then dark over time due to self-] from radium's ].<ref name=k4/> Insoluble radium compounds ] with all barium, most ], and most ] compounds.<ref name=k8>Kirby et al., p. 8</ref> | |||
| ] (RaO) has not been characterized, despite oxides being common compounds for the other alkaline earth metals. ] (Ra(OH)<sub>2</sub>) is the most readily soluble among the alkaline earth hydroxides and is a stronger base than its barium congener, ].<ref name=k4to8>Kirby et al., pp. 4–8</ref> It is also more soluble than ] and ]: these three adjacent hydroxides may be separated by precipitating them with ].<ref name=k4to8/> | |||
| ] (RaCl<sub>2</sub>) is a colorless, luminous compound. It becomes yellow after some time due to self-damage by the ] given off by radium when it decays. Small amounts of barium impurities give the compound a rose color.<ref name=k4to8/> It is soluble in water, though less so than ], and its solubility decreases with increasing concentration of ]. Crystallization from aqueous solution gives the dihydrate RaCl<sub>2</sub>·2H<sub>2</sub>O, isomorphous with its barium analog.<ref name=k4to8/> | |||
| ] (RaBr<sub>2</sub>) is also a colorless, luminous compound.<ref name=k4to8/> In water, it is more soluble than radium chloride. Like radium chloride, crystallization from aqueous solution gives the dihydrate RaBr<sub>2</sub>·2H<sub>2</sub>O, isomorphous with its barium analog. The ionizing radiation emitted by radium bromide excites ] molecules in the air, making it glow. The ]s emitted by radium quickly gain two electrons to become neutral ], with builds up inside and weakens radium bromide crystals. This effect sometimes causes the crystals to break or even explode.<ref name=k4to8/> | |||
| ] (Ra(NO<sub>3</sub>)<sub>2</sub>) is a white compound that can be made by dissolving ] in ]. As the concentration of nitric acid increases, the solubility of radium nitrate decreases, an important property for the chemical purification of radium.<ref name=k4to8/> | |||
| Radium forms much the same insoluble salts as its lighter congener barium: it forms the insoluble ] (RaSO<sub>4</sub>, the most insoluble known sulfate), ] (RaCrO<sub>4</sub>), ] (RaCO<sub>3</sub>), ] (Ra(IO<sub>3</sub>)<sub>2</sub>), ] (RaBeF<sub>4</sub>), and nitrate (Ra(NO<sub>3</sub>)<sub>2</sub>). With the exception of the carbonate, all of these are less soluble in water than the corresponding barium salts. Additionally, ], ], and ] are probably also insoluble, as they ] with the corresponding insoluble barium salts.<ref name=k8to9>Kirby et al., pp. 8–9</ref> The great insolubility of radium sulfate (at 20 °C, only 2.1 ] will dissolve in 1 ] of water) means that it is one of the less biologically dangerous radium compounds.<ref name=k12>Kirby et al., p. 12</ref> | |||
| ===Isotopes=== | |||
| {{main article|Isotopes of radium}} | |||
| Radium has 33 known isotopes, with ]s from 202 to 234: all of them are ].<ref name=NUBASE>{{cite journal |author=G. Audi |author2=A. H. Wapstra |author3=C. Thibault|author4=J. Blachot |author5=O. Bersillon |last-author-amp=yes |year=2003 |title=The NUBASE evaluation of nuclear and decay properties |url=http://amdc.in2p3.fr/nubase/Nubase2003.pdf |journal=] |volume=729 |pages=3–128 |doi=10.1016/j.nuclphysa.2003.11.001 |bibcode=2003NuPhA.729....3A}}</ref> Four of these – <sup>223</sup>Ra (] 11.4 days), <sup>224</sup>Ra (3.64 days), <sup>226</sup>Ra (1600 years), and <sup>228</sup>Ra (5.75 years) – occur naturally in the ]s of primordial ]-232, ], and ] (<sup>223</sup>Ra from uranium-235, <sup>226</sup>Ra from uranium-238, and the other two from thorium-232). These isotopes nevertheless still have half-lives too short to be ] and only exist in nature from these decay chains.<ref name=k3>Kirby et al., p. 3</ref> Together with the ] <sup>225</sup>Ra (15 d), these are the five most stable isotopes of radium.<ref name=k3/> All other known radium isotopes have half-lives under two hours, and the majority have half-lives under a minute.<ref name=NUBASE/> At least 12 ]s have been reported; the most stable of them is radium-205m, with a half-life of between 130 and 230 milliseconds, which is still shorter than thirty-four ] radium isotopes.<ref name=NUBASE/> | |||
| In the early history of the study of radioactivity, the different natural isotopes of radium were given different names. In this scheme, <sup>223</sup>Ra was named actinium X (AcX), <sup>224</sup>Ra thorium X (ThX), <sup>226</sup>Ra radium (Ra), and <sup>228</sup>Ra mesothorium 1 (MsTh<sub>1</sub>).<ref name=k3/> When it was realized that all of these are isotopes of radium, many of these names fell out of use, and "radium" came to refer to all isotopes, not just <sup>226</sup>Ra.<ref name=k3/> Some of radium-226's decay products received historical names including "radium", ranging from radium A to radium G.<ref name=k3/> | |||
| <sup>226</sup>Ra is the most stable isotope of radium and is the last isotope in the (4''n'' + 2) decay chain of uranium-238 with a half-life of over a millennium: it makes up almost all of natural radium. Its immediate decay product is the dense radioactive ] ], which is responsible for much of the danger of environmental radium.<ref>. ].</ref> It is 2.7 million times more radioactive than the same ] of natural ] (mostly uranium-238), due to its proportionally shorter half-life.<ref>{{cite book | url = https://books.google.com/books?id=ojaelt2o7AQC&pg=PA139 | pages = 139– | title = The Interpretation of Radium | isbn = 978-0-486-43877-1 | author1 = Soddy | first1 = Frederick | date = 25 August 2004}}</ref><ref>{{cite book | url = https://books.google.com/books?id=t-fpKQ54f44C&pg=PT115| pages = 115– | title = Radioactivity | isbn = 978-0-19-983178-4 |publisher=Oxford University Press| author1 = Malley | first1 = Marjorie C | date = 2011}}</ref> | |||
| A sample of radium metal maintains itself at a higher ] than its surroundings because of the radiation it emits – ], ], and ]. More specifically, natural radium (which is mostly <sup>226</sup>Ra) emits mostly alpha particles, but other steps in its decay chain (the ]) emit alpha or beta particles, and almost all particle emissions are accompanied by gamma rays.<ref>{{cite book | url = https://books.google.com/books?id=alC0vvE-ZUwC&pg=PA133| pages = 133– | title = The Becquerel Rays and the Properties of Radium | isbn = 978-0-486-43875-7 | author1 = Strutt | first1 = R. J | date = 7 September 2004}}</ref> | |||
| ==History== | |||
| ]]] | |||
| ] | |||
| ===Discovery=== | |||
| {{Details|Marie Curie#New elements}} | |||
| Radium was ] by ] and her husband ] on 21 December 1898, in a ] sample.<ref name=crc>Hammond, C. R. "Radium" in {{RubberBible92nd}}</ref> While studying the mineral earlier, the Curies removed uranium from it and found that the remaining material was still radioactive. They separated out an element similar to ] from pitchblende in July 1898, that turned out to be ]. They then separated out a radioactive mixture consisting mostly of two components: compounds of ], which gave a brilliant green flame color, and unknown radioactive compounds which gave ] ]s that had never been documented before. The Curies found the radioactive compounds to be very similar to the barium compounds, except that they were more insoluble. This made it possible for the Curies to separate out the radioactive compounds and discover a new element in them. The Curies announced their discovery to the ] on 26 December 1898.<ref>{{cite journal |year=1898|title=Sur une nouvelle substance fortement radio-active, contenue dans la pechblende (On a new, strongly radioactive substance contained in pitchblende)|journal=Comptes Rendus|volume= 127|pages= 1215–1217|url=http://www.aip.org/history/curie/discover.htm |accessdate=1 August 2009 |author=Curie, Pierre |author2=Curie, Marie |author3=Bémont, Gustave |last-author-amp=yes }}</ref><ref>{{cite journal | doi = 10.1021/ed010p79 | title = The discovery of the elements. XIX. The radioactive elements |year = 1933 | last1 = Weeks | first1 = Mary Elvira |authorlink1=Mary Elvira Weeks| journal = Journal of Chemical Education | volume = 10 | issue = 2 | pages = 79|bibcode = 1933JChEd..10...79W }}</ref> The naming of radium dates to about 1899, from the French word ''radium'', formed in Modern Latin from ''radius'' (''ray''): this was in recognition of radium's power of emitting energy in the form of rays.<ref>{{cite journal|author=Ball, David W. |url=http://superieur.deboeck.com/resource/extra/9782804171278/mcquarrie_interA.pdf|journal=Journal of Chemical Education| volume =62 |year=1985|pages =787–788|title=Elemental etymology: What's in a name?|doi=10.1021/ed062p787}}</ref><ref name="Carvalho2011">{{cite journal|last1=Carvalho|first1=Fernando P.|title=Marie Curie and the Discovery of Radium|year=2011|pages=3–13|doi=10.1007/978-3-642-22122-4_1}}</ref><ref name="Weeks1933">{{cite journal|last1=Weeks|first1=Mary Elvira|title=The discovery of the elements. XIX. The radioactive elements|journal=Journal of Chemical Education|volume=10|issue=2|year=1933|pages=79|doi=10.1021/ed010p79|bibcode=1933JChEd..10...79W}}</ref> | |||
| ===Subsequent developments=== | |||
| In 1910, radium was isolated as a pure ] by Marie Curie and ] through the ] of a pure radium ] (RaCl<sub>2</sub>) solution using a ] ], producing a radium–mercury ]. This amalgam was then heated in an atmosphere of ] gas to remove the mercury, leaving pure radium metal.<ref>{{cite journal|author=Curie, Marie|author2=Debierne, André|last-author-amp=yes |year=1910|title=Sur le radium métallique" (On metallic radium)|journal=Comptes Rendus|volume=151 |pages=523–525 |url=http://visualiseur.bnf.fr/CadresFenetre?O=NUMM-3104&I=523&M=tdm |language=French|accessdate=1 August 2009}}</ref> The same year, E. Eoler isolated radium by ] of its ], Ra(N<sub>3</sub>)<sub>2</sub>.<ref name=k3/> Radium metal was first industrially produced in the beginning of the 20th century by ], a subsidiary company of ] (UMHK) in its ] plant in Belgium.<ref>{{cite book | page = 206 | url = https://books.google.com/books?id=yCkJgKwyAVoC&pg=PA206 | title = Biotechnology for waste management and site restoration: Technological, educational, business, political aspects | isbn = 978-0-7923-4769-9 | author1 = Ronneau, C. | author2 = Bitchaeva, O. | publisher = Scientific Affairs Division, North Atlantic Treaty Organization | date = 1997}}</ref> | |||
| The common historical unit for radioactivity, the ], is based on the radioactivity of <sup>226</sup>Ra.<ref>{{cite web | author = Frame, Paul W. | title = How the Curie Came to Be | url = http://www.orau.org/ptp/articlesstories/thecurie.htm | accessdate = 30 April 2008}}</ref> | |||
| ==Occurrence== | |||
| All isotopes of radium have half-lives much shorter than the ], so that any primordial radium would have decayed long ago. Radium nevertheless still occurs ], as the isotopes <sup>223</sup>Ra, <sup>224</sup>Ra, <sup>226</sup>Ra, and <sup>228</sup>Ra are part of the decay chains of natural thorium and uranium isotopes.<ref name=k3/> Of these four isotopes, the most long-lived is <sup>226</sup>Ra (half-life 1600 years), a decay product of natural uranium. Because of its relative longevity, <sup>226</sup>Ra is the most common isotope of the element, making up about one ] of the Earth's crust; essentially all natural radium is <sup>226</sup>Ra.<ref name=Greenwood109/> Thus, radium is found in tiny quantities in the uranium ore ] and various other uranium ], and in even tinier quantities in thorium minerals. One ] of ] typically yields about one seventh of a ] of radium.<ref>, Los Alamos National Laboratory. Retrieved 5 August 2009.</ref> One kilogram of the ] contains about 900 ]s of radium, and one ] of ] contains about 89 ]s of radium.<ref name=Raabundance>Section 14, Geophysics, Astronomy, and Acoustics; Abundance of Elements in the Earth's Crust and in the Sea, in Lide, David R. (ed.), ''], 85th Edition''. CRC Press. Boca Raton, Florida (2005).</ref> | |||
| ==Extraction== | |||
| In the first extraction of radium Curie used the residues after extraction of uranium from pitchblende. The uranium had been extracted by dissolution in sulfuric acid leaving radium sulfate, which is similar to barium sulfate but even less soluble in the residues. The residues also contained rather substantial amounts of barium sulfate which thus acted as a carrier for the radium sulfate. The first steps of the radium extraction process involved boiling with sodium hydroxide followed by hydrochloric acid treatment to remove as much as possible of other compounds. The remaining residue was then treated with sodium carbonate to convert the barium sulfate into barium carbonate carrying the radium, thus making it soluble in hydrochloric acid. After dissolution the barium and radium are reprecipitated as sulfates and this was repeated one or few times, for further purification of the mixed sulfate. Some impurities, that form insoluble sulfides, were removed by treating the chloride solution with hydrogen sulfide followed by filtering. When the mixed sulfate were pure enough they were once more converted to mixed chloride and barium and radium were separated by ] while monitoring the progress using a ] (radium gives characteristic red lines in contrast to the green barium lines), and the ].<ref>. ''lateralscience.blogspot.se''. November 2012</ref> A similar process was still used for industrial radium extraction in 1940, but mixed bromides were then used for the fractionation.<ref>{{Cite journal | doi = 10.1021/ed017p417| title = Extraction of radium from Canadian pitchblende| journal = Journal of Chemical Education| volume = 17| issue = 9| pages = 417| year = 1940| last1 = Kuebel | first1 = A. | bibcode = 1940JChEd..17..417K}}</ref> If the barium content of the uranium ore is not high enough it is easy to add some to carry the radium. These processes were applied to high grade uranium ores but may not work well with low grade ores. The small amounts radium that are produced today are still extracted from uranium ore by this method.<ref name=Greenwood109>Greenwood and Earnshaw, pp. 109–110</ref> | |||
| ==Production== | |||
| Uranium had no large scale application in the late 19th century and therefore no large uranium mines existed. In the beginning the only larger source for uranium ore was the ] mines in Joachimsthal, ] (now ], Czech Republic).<ref name=crc/> The uranium ore was only a by-product of the mining activities. After the isolation of radium by Marie and Pierre Curie from uranium ore from Joachimsthal several scientists started to isolate radium in small quantities. Later small companies purchased mine tailings from Joachimsthal mines and started isolating radium. In 1904 the Austrian government ] the mines and stopped exporting raw ore. For some time the radium availability was low.<ref>{{cite journal | doi = 10.1007/s00048-008-0308-z | title = Tauschwirtschaft, Reputationsökonomie, Bürokratie |year = 2008 | last1 = Ceranski | first1 = Beate | journal = NTM Zeitschrift für Geschichte der Wissenschaften, Technik und Medizin | volume = 16 | issue = 4 | pages = 413–443}}</ref> | |||
| The formation of an Austrian monopoly and the strong urge of other countries to have access to radium led to a worldwide search for uranium ores. The United States took over as leading producer in the early 1910s. The ] sands in ] provide some of the element, but richer ores are found in the ] and the area of the ] and the ] of northwestern Canada.<ref name=crc/><ref>{{cite journal | jstor = 40796935|author=Just, Evan|author2=Swain, Philip W.|author3=Kerr, William A.|last-author-amp=yes |journal=Financial Analysts Journal|volume=8|issue=1|year=1952 |pages=85–93|title=Peacetíme Impact of Atomíc Energy | doi = 10.2469/faj.v8.n1.85}}</ref> Neither of the deposits is mined for radium but the uranium content makes mining profitable. | |||
| The amounts of radium produced were and are always relatively small; for example, in 1918, 13.6 g of radium were produced in the United States.<ref>{{cite journal | doi = 10.1126/science.49.1262.227 | title = Radium Production |year = 1919 | last1 = Viol | first1 = C. H. | journal = Science | volume = 49 | issue = 1262 | pages = 227–8 | pmid = 17809659|bibcode = 1919Sci....49..227V }}</ref> In 1954, the total worldwide supply of purified radium amounted to about 5 pounds (2.3 kg),<ref name="PMC2024184">{{cite journal|title=Radium in the healing arts and in industry: Radiation exposure in the United States|pmc=2024184|year=1954|volume=69|issue=3|pmid=13134440|last1=Terrill Jr|first1=JG|last2=Ingraham Sc|first2=2nd|last3=Moeller|first3=DW|pages=255–62|journal=Public health reports|doi=10.2307/4588736}}</ref> and it is still in this range today, while the annual production of pure radium compounds is only about 100 g in total today.<ref name=Greenwood109/> The chief radium-producing countries are Belgium, Canada, the Czech Republic, ], the United Kingdom, and ].<ref name=Greenwood109/> | |||
| ==Applications== | |||
| Some of the few practical uses of radium are derived from its radioactive properties. More recently discovered ]s, such as ] and ], are replacing radium in even these limited uses because several of these isotopes are more powerful emitters, safer to handle, and available in more concentrated form.<ref>{{cite book | url = https://books.google.com/books?id=3cT2REdXJ98C&pg=PA24| page =24 | title = Radiation source use and replacement: Abbreviated version | isbn = 978-0-309-11014-3 | author1 = Committee On Radiation Source Use And Replacement | first1 = National Research Council (U.S.) | last2 = Nuclear And Radiation Studies Board | first2 = National Research Council (U.S.) | date = January 2008}}</ref><ref>{{cite book | url = https://books.google.com/books?id=bk0go_-FO5QC&pg=PA8| page =8 | title = Radiation therapy planning | isbn = 978-0-07-005115-7 | author1 = Bentel | first1 = Gunilla Carleson | date = 1996}}</ref> | |||
| ===Historical=== | |||
| ====Luminescent paint==== | |||
| ] | |||
| ] | |||
| Radium was formerly used in ] paints for watches, nuclear panels, aircraft switches, clocks, and instrument dials. A typical self-luminous watch that uses radium paint contains around 1 microgram of radium.<ref name="PMC2024184" /> In the mid-1920s, a lawsuit was filed against the ] by five dying "]" dial painters who had painted radium-based ] on the dials of watches and clocks. The dial painters routinely licked their brushes to give them a fine point, thereby ingesting radium.<ref name=OakRidge>Frame, Paul. , ]. Retrieved September 17, 2007.</ref> Their exposure to radium caused serious health effects which included sores, ], and ]. This is because radium is treated as ] by the body, and ], where radioactivity degrades ] and can mutate ].<ref name=epa/> | |||
| During the litigation, it was determined that the company's scientists and management had taken considerable precautions to protect themselves from the effects of radiation, yet had not seen fit to protect their employees. Additionally, for several years the companies had attempted to cover up the effects and avoid liability by insisting that the Radium Girls were instead suffering from ]. This complete disregard for employee welfare had a significant impact on the formulation of ] ].<ref>{{cite web|url=http://66.147.244.135/~enviror4/people/radiumgirls/ |title=Environmental history timeline – Radium Girls|accessdate=29 December 2014}}</ref> | |||
| As a result of the lawsuit, the adverse effects of radioactivity became widely known, and radium-dial painters were instructed in proper safety precautions and provided with protective gear. In particular, dial painters no longer licked paint brushes to shape them (which caused some ingestion of radium salts). Radium was still used in dials as late as the 1960s, but there were no further injuries to dial painters. This highlighted that the harm to the Radium Girls could easily have been avoided.<ref>Rowland, R. E. (1995) . Argonne National Laboratory. p. 22</ref> | |||
| From the 1960s the use of radium paint was discontinued. In many cases luminous dials were implemented with non-radioactive fluorescent materials excited by light; such devices glow in the dark after exposure to light, but the glow fades.<ref name=epa/> Where long-lasting self-luminosity in darkness was required, safer radioactive ]-147 (half-life 2.6 years) or ] (half-life 12 years) paint was used; both continue to be used today.<ref>{{Cite book|title = Man-made and natural radioactivity in environmental pollution and radiochronology|date = 2004|page = 78|isbn = 1-4020-1860-6|last1 = Tykva|first1 = Richard|last2 = Berg|first2 = Dieter|publisher=Springer}}</ref> These had the added advantage of not degrading the phosphor over time, unlike radium.<ref>{{cite book |script-title=ru:Аналитическая химия технеция, прометия, астатина и франция |trans-title=Analytical Chemistry of Technetium, Promethium, Astatine, and Francium |language=Russian |first1=A. K. |last1=Lavrukhina |first2=A. A. |last2=Pozdnyakov |date=1966 |publisher=] |page=118}}</ref> Tritium emits very low-energy ] (even lower-energy than the beta radiation emitted by promethium)<ref name=NUBASE/> which cannot penetrate the skin,<ref>. ehso.emory.edu</ref> rather than the penetrating gamma radiation of radium and is regarded as safer.<ref name=ieer>{{cite web|author=Zerriffi, Hisham |date=January 1996|title=Tritium: The environmental, health, budgetary, and strategic effects of the Department of Energy's decision to produce tritium|url=http://www.ieer.org/reports/tritium.html#(11)|publisher=]|accessdate=15 September 2010}}</ref> | |||
| Clocks, watches, and instruments dating from the first half of the 20th century, often in military applications, may have been painted with radioactive luminous paint. They are usually no longer luminous; however, this is not due to radioactive decay of the radium (which has a half-life of 1600 years) but to the fluorescence of the zinc sulfide fluorescent medium being worn out by the radiation from the radium.<ref name=emsley>{{cite book|author=Emsley, John |title=Nature's building blocks: an A-Z guide to the elements|url=https://books.google.com/books?id=j-Xu07p3cKwC&pg=PA351|date=2003|publisher=Oxford University Press|isbn=978-0-19-850340-8|pages=351–}}</ref> The appearance of an often thick layer of green or yellowish brown paint in devices from this period suggests a radioactive hazard. The radiation dose from an intact device is relatively low and usually not an acute risk; but the paint is dangerous if released and inhaled or ingested.<ref name=brit>. ''Encyclopædia Britannica''</ref><ref>. vintagewatchstraps.com</ref> | |||
| ====Commercial use==== | |||
| ] | |||
| {{Main article|Radioactive quackery }} | |||
| Radium was once an additive in products such as toothpaste, hair creams, and even food items due to its supposed curative powers.<ref>{{cite web|accessdate=1 August 2009|title=French Web site featuring products (medicines, mineral water, even underwear) containing radium|url=http://www.dissident-media.org/infonucleaire/radieux.html}}</ref> Such products soon fell out of vogue and were prohibited by authorities in many countries after it was discovered they could have serious adverse health effects. (See, for instance, '']'' or '']'' types of "Radium water" or "Standard Radium Solution for Drinking".)<ref name=emsley/> ] featuring radium-rich water are still occasionally touted as beneficial, such as those in ], Japan. In the U.S., nasal radium irradiation was also administered to children to prevent middle-ear problems or enlarged tonsils from the late 1940s through the early 1970s.<ref name="Baltimore">{{cite news|url=http://baltimorechronicle.com/rupnose.html|title=Nasal Radium Irradiation of Children Has Health Fallout|last=Cherbonnier|first=Alice|date=1 October 1997|work=Baltimore Chronicle|accessdate=1 August 2009}}</ref> | |||
| ====Medical use==== | |||
| Radium (usually in the form of ] or ]) was used in ] to produce radon gas which in turn was used as a ] treatment; for example, several of these radon sources were used in Canada in the 1920s and 1930s.<ref name=brit/><ref>{{cite book|url = https://books.google.com/?id=NtKUdnjaCxMC&pg=PA135| title = An Element of Hope: Radium and the Response to Cancer in Canada, 1900–1940|first = Charles|last = Hayter|publisher = McGill-Queen's Press|date = 2005|isbn = 978-0-7735-2869-7|chapter = The Politics of Radon Therapy in the 1930s}}</ref> However, many treatments that were used in the early 1900s are not used anymore because of the harmful effects radium bromide exposure caused. Some examples are ], cancer, and ].<ref name="Harvie">{{cite journal | doi = 10.1016/S0160-9327(99)01201-6| pmid = 10589294| title = The radium century| journal = Endeavour| volume = 23| issue = 3| pages = 100–5|year = 1999| last1 = Harvie| first1 = David I.}}</ref> | |||
| ], one of the founding physicians of ], was a major pioneer in the medical use of radium to treat cancer.<ref>{{cite web | |||
| | url = http://www.hopkinsmedicine.org/about/history/history5.html | |||
| | title=The Four Founding Physicians | |||
| | accessdate = 10 April 2013 | |||
| }}</ref> His first patient was his own aunt in 1904, who died shortly after surgery.<ref name="DasturTank2011">{{cite journal|last1=Dastur|first1=Adi E.|last2=Tank|first2=P. D.|title=Howard Atwood Kelly: much beyond the stitch|journal=The Journal of Obstetrics and Gynecology of India|volume=60|issue=5|year=2011|pages=392–394|doi=10.1007/s13224-010-0064-6}}</ref> Kelly was known to use excessive amounts of radium to treat various cancers and tumors. As a result, some of his patients died from high amounts of radium exposure.<ref name="AronowitzRobison2010">{{cite journal|last1=Aronowitz|first1=Jesse N.|last2=Robison|first2=Roger F.|title=Howard Kelly establishes gynecologic brachytherapy in the United States|journal=Brachytherapy|volume=9|issue=2|year=2010|pages=178–184|doi=10.1016/j.brachy.2009.10.001|pmid=20022564}}</ref> His method of radium application was inserting a radium capsule near the affected area then sewing the radium "points" directly to the ].<ref name="AronowitzRobison2010" /> This was the same method used to treat ], the host of the original ], for ].<ref name="Skloot2010">{{cite book|author=Rebecca Skloot|title=The Immortal Life of Henrietta Lacks|url=https://books.google.com/books?id=LBBhikJpLjwC|accessdate=8 April 2013|date=2 February 2010|publisher=Random House Digital, Inc.|isbn=978-0-307-58938-5}}</ref> Currently, safer and more available radioisotopes are usually used instead.<ref name=epa/> | |||
| ===Current=== | |||
| The isotope <sup>223</sup>Ra (under the trade name ]) was approved by the United States ] in 2013 for use in ] as a ] treatment of bone ].<ref name=FBT-FDA2013>{{Cite web|title=FDA OKs pinpoint prostate cancer radiation drug Xofigo from Bayer, Algeta |url=http://www.fiercebiotech.com/story/breaking-fda-oks-pinpoint-prostate-cancer-radiation-drug-xofigo-bayer-alget/2013-05-15 |archiveurl=http://www.webcitation.org/6Gdfdbr1u |archivedate=2013-05-15 |deadurl=no }}</ref><ref>. cancer.org. (2013-05-15)</ref> The main indication of treatment with ] is the therapy of bony metastases from castration-resistant prostate cancer due to the favourable characteristics of this alpha-emitter radiopharmaceutical.<ref>{{cite journal |pmid=26222274 | volume=59 | title=New radiopharmaceutical agents for the treatment of castration-resistant prostate cancer | year=2015 | journal=Q J Nucl Med Mol Imaging | pages=420–38 | last1 = Maffioli | first1 = L | last2 = Florimonte | first2 = L | last3 = Costa | first3 = DC | last4 = Correia Castanheira | first4 = J | last5 = Grana | first5 = C | last6 = Luster | first6 = M | last7 = Bodei | first7 = L | last8 = Chinol | first8 = M}}</ref> | |||
| Radium is still used today as a radiation source in some ] devices to check for flawed metallic parts, similarly to ].<ref name=epa/> When mixed with ], radium acts as a ].<ref name=emsley/><ref>{{cite book | url = https://books.google.com/books?id=YpEiPPFlNAAC&pg=PA261 | pages = 260–261 | chapter = Alpha particle induced nuclear reactions | title = Radioactivity: Introduction and history | isbn = 978-0-444-52715-8 | author1 = l'Annunziata | first1 = Michael F | date = 2007|publisher=Elsevier}}</ref> Radium-beryllium neutron sources are still sometimes used even today,<ref name=epa> – US EPA</ref><ref>{{Cite journal | |||
| | pmid = 15069300 | |||
| | year = 2004 | |||
| | author1 = Holden | |||
| | first1 = N. E. | |||
| | title = Radiation dosimetry of a graphite moderated radium-beryllium source | |||
| | journal = Health physics | |||
| | volume = 86 | |||
| | issue = 5 Suppl | |||
| | pages = S110–2 | |||
| | last2 = Reciniello | |||
| | first2 = R. N. | |||
| | last3 = Hu | |||
| | first3 = J. P. | |||
| | last4 = Rorer | |||
| | first4 = David C. | |||
| | bibcode = 2003rdtc.conf..484H | |||
| | doi = 10.1142/9789812705563_0060 | |||
| }}</ref> but other materials such as ] are now more common: about 1500 polonium-beryllium neutron sources, with an individual activity of {{convert|1850|Ci|TBq|abbr=on}}, have been used annually in ].<ref> (in Russian). stringer.ru (2006-11-26).</ref> | |||
| ==Precautions== | |||
| Radium is highly radioactive and its immediate daughter, ] gas, is also radioactive. When ingested, 80% of the ingested radium leaves the body through the ], while the other 20% goes into the ], mostly accumulating in the bones.<ref name=epa/> Exposure to radium, internal or external, can cause cancer and other disorders, because radium and radon emit alpha and ]s upon their decay, which kill and mutate cells.<ref name=epa/> At the time of the ] in 1944, the "tolerance dose" for workers was set at 0.1 microgram of ingested radium.<ref>{{cite book|author=Weisgall, Jonathan M.|title=Operation crossroads: the atomic tests at Bikini Atoll|url=https://books.google.com/books?id=K63bAAAAMAAJ|accessdate=20 August 2011|date=1994|publisher=Naval Institute Press|isbn=978-1-55750-919-2|page=238}}</ref><ref>{{cite journal | doi = 10.2307/3579805| first =Shirley A. | last =Fry| title = Supplement: Madame Curie's Discovery of Radium (1898): A Commemoration by Women in Radiation Sciences | journal =Radiation Research | volume= 150 | issue = 5 |year = 1998 | pages = S21–S29 | pmid = 9806606}}</ref><!-- http://www.osti.gov/accomplishments/documents/fullText/ACC0029.pdf--> | |||
| Some of the biological effects of radium were apparent from the start. The first case of so-called "radium-dermatitis" was reported in 1900, only 2 years after the element's discovery. The French physicist ] carried a small ampoule of radium in his waistcoat pocket for 6 hours and reported that his skin became ]. Pierre and Marie Curie were so intrigued by radiation that they sacrificed their own health to learn more about it. Pierre Curie attached a tube filled with radium to his arm for ten hours. Oddly enough, he was delighted to see that a skin lesion had appeared. This was a major breakthrough for science. It posed a question: if radium was capable of destroying healthy tissue, could it also attack cancerous tissue?<ref>{{cite book|last1=Redniss|first1=Lauren|title=Radioactive: Marie & Pierre Curie: A Tale Of Love And Fallout|date=2011|publisher=HarperCollins|location=New York, NY|isbn=978-0-06-135132-7|page=70}}</ref> Handling of radium has been blamed for Marie Curie's death due to ]. However, most of radium's danger comes from its daughter radon: being a gas, it can enter the body far more readily than can its parent radium.<ref name=epa/> | |||
| ==See also== | |||
| {{Subject bar | |||
| |portal1=Chemistry | |||
| |portal2=Medicine | |||
| |book1=Radium | |||
| |book2=Period 7 elements | |||
| |book3=Alkaline earth metals | |||
| |book4=Chemical elements (sorted alphabetically) | |||
| |book5=Chemical elements (sorted by number) | |||
| |commons=y | |||
| |wikt=y | |||
| |wikt-search=radium | |||
| |v=y | |||
| |v-search=Radium atom | |||
| }} | |||
| ==Notes== | |||
| {{notelist}} | |||
| ==References== | |||
| {{Reflist|35em}} | |||
| ==Bibliography== | |||
| * {{cite book | url = http://library.lanl.gov/cgi-bin/getfile?rc000041.pdf| title = The Radiochemistry of Radium|ref=Kirby | last1 = Kirby | first1 = H. W | last2 = Salutsky | first2 = Murrell L | date = 1964 | publisher=National Academies Press}} | |||
| * {{Greenwood&Earnshaw2nd}} | |||
| ==Further reading== | |||
| * {{cite book|title=Guide to the Elements – Revised Edition|author=Albert Stwertka|publisher=Oxford University Press|date=1998|isbn=0-19-508083-1}} | |||
| * {{cite news|url=http://www.nytimes.com/library/national/science/100698sci-radium.html|title=A Glow in the Dark, and a Lesson in Scientific Peril|date=6 October 1998|author=Denise Grady|accessdate=25 December 2007|work=The New York Times}} | |||
| * {{cite web|url=http://nobelprize.org/nobel_prizes/physics/articles/curie/index.html|title=Marie and Pierre Curie and the Discovery of Polonium and Radium|publisher=Nobel Foundation|author=Nanny Fröman|date=1 December 1996|accessdate=25 December 2007}} | |||
| * {{cite journal|title = The great radium scandal|author = Macklis, R. M.|journal = Scientific American|year = 1993|volume = 269|issue = 2|pages = 94–99|pmid = 8351514|doi = 10.1038/scientificamerican0893-94}} | |||
| * {{cite book|title = Radium Girls: Women and Industrial Health Reform, 1910–1935|author = Clark, Claudia|date = 1987|publisher = University of North Carolina Press|isbn = 0-8078-4640-6}} | |||
| * {{cite book|last=Curie |first=Marie |authorlink=Marie Curie|title=]|year=1921|publisher=Vassar College|location=Poughkeepsie}} | |||
| ==External links== | |||
| * | |||
| * | |||
| * | |||
| * | |||
| * | |||
| * at '']'' (University of Nottingham) | |||
| * (Created and maintained by physicists) | |||
| {{clear}} | |||
| {{Compact periodic table}} | |||
| {{Authority control}} | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
Revision as of 14:08, 15 September 2016
Radium=Ra and is the 6th element in group 2 of the periodic table. It has a atomic mas of 88