Radium 25602 226117992 2008-07-16T22:05:52Z Arkuat 29003 /* Characteristics */ section title according to [[WP:WikiProject Elements]] {{otheruses}} {{Elementbox_header | number=88 | symbol=Ra | name=radium | left= [[francium]] | right=[[actinium]] | above=[[barium|Ba]] | below=[[Unbinilium|Ubn]] | color1=#ffdead | color2=black }} {{Elementbox_series | [[alkaline earth metal]]s }} {{Elementbox_groupperiodblock | group=2 | period=7 | block=s }} {{Elementbox_appearance | silvery white metallic }} {{Elementbox_atomicmass_gpm | (226) }} {{Elementbox_econfig | &#91;[[radon|Rn]]&#93; 7s² }} {{Elementbox_epershell | 2, 8, 18, 32, 18, 8, 2 }} {{Elementbox_section_physicalprop | color1=#ffdead | color2=black }} {{Elementbox_phase | [[solid]] }} {{Elementbox_density_gpcm3nrt | 5.5 }} {{Elementbox_meltingpoint | k=973 | c=700 | f=1292 }} {{Elementbox_boilingpoint | k=2010 | c=1737 | f=3159 }} {{Elementbox_heatfusion_kjpmol | 8.5 }} {{Elementbox_heatvaporiz_kjpmol | 113 }} {{Elementbox_vaporpressure_katpa | 819 | 906 | 1037 | 1209 | 1446 | 1799 | comment= }} {{Elementbox_section_atomicprop | color1=#ffdead | color2=black }} {{Elementbox_crystalstruct | cubic body centered }} {{Elementbox_oxistates | 2<br />(strongly [[base (chemistry)|basic]] oxide) }} {{Elementbox_electroneg_pauling | 0.9 }} {{Elementbox_ionizationenergies2 | 509.3 | 979.0 }} {{Elementbox_atomicradius_pm | 215 }} {{Elementbox_section_miscellaneous | color1=#ffdead | color2=black }} {{Elementbox_magnetic | nonmagnetic }} {{Elementbox_eresist_ohmmat20 | 1 µ}} {{Elementbox_thermalcond_wpmkat300k | 18.6 }} {{Elementbox_cas_number | 7440-14-4 }} {{Elementbox_isotopes_begin | color1=#ffdead | color2=black }} {{Elementbox_isotopes_decay | mn=223 | sym=Ra | na=? | hl=11.43 [[day|d]] | dm=[[alpha emission|alpha]] | de=5.99 | pn=219 | ps=[[radon|Rn]] }} {{Elementbox_isotopes_decay | mn=224 | sym=Ra | na=? | hl=3.6319 [[day|d]] | dm=[[alpha emission|alpha]] | de=5.789 | pn=220 | ps=[[radon|Rn]] }} {{Elementbox_isotopes_decay | mn=226 | sym=Ra | na=[[trace radioisotope|trace]] | hl=1602 [[year|y]] | dm=[[alpha emission|alpha]] | de=4.871 | pn=222 | ps=[[radon|Rn]] }} {{Elementbox_isotopes_decay | mn=228 | sym=Ra | na=[[synthetic radioisotope|syn]] | hl=6.7 y | dm=[[beta emission|beta<sup>-</sup>]] | de=0.046 | pn=228 | ps=[[actinium|Ac]] }} {{Elementbox_isotopes_end}} {{Elementbox_footer | color1=#ffdead | color2=black }} '''Radium''' ({{pronEng|ˈreɪdiəm}}) is a radioactive [[chemical element]] which has the symbol '''Ra''' and [[atomic number]] 88. Its appearance is almost pure white, but it readily [[oxidize]]s on exposure to air, turning black. Radium is an [[alkaline earth metal]] that is found in trace amounts in [[uranium]] ores. It is extremely [[radioactive]]. Its most stable [[isotope]], '''{{SimpleNuclide|Radium|226}}''', has a [[half-life]] of 1602 years and decays into [[radon]] gas. == Characteristics == The heaviest of the [[alkaline earth metal]]s, radium is intensely radioactive and resembles [[barium]] in its chemical behavior. This metal is found in tiny quantities in the uranium ore [[uraninite|pitchblende]], and various other uranium [[minerals]]. Radium preparations are remarkable for maintaining themselves at a higher [[temperature]] than their surroundings, and for their radiations, which are of three kinds: [[alpha particles]], [[beta particles]], and [[gamma rays]]. Radium also produces [[neutron]]s when mixed with [[beryllium]]. When freshly prepared, pure radium metal is brilliant white, but blackens when exposed to air (probably due to [[nitride]] formation). Radium is [[luminescence|luminescent]] (giving a faint blue color), reacts violently with [[water]] and [[oil]] to form [[radium hydroxide]] and is slightly more volatile than [[barium]]. The normal phase of radium is a solid. == Applications == Some of the few practical uses of radium are derived from its radioactive properties. More recently discovered [[radioisotope]]s, such as {{SimpleNuclide|link|Cobalt|60}} and {{SimpleNuclide|link|Caesium|137}}, 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. When mixed with [[beryllium]] it is a [[neutron source]] for [[physics]] experiments. ===Historical uses=== Radium was formerly used in [[luminescence|self-luminous]] paints for watches, nuclear panels, aircraft switches, clocks, and instrument dials. More than 100 former [[Radium Girls|watch dial painters]] who used their lips to shape the paintbrush died from the radiation from the radium that had become stored in their bones. Soon afterward, the adverse effects of radioactivity became widely known. Radium was still used in dials as late as the 1950s. Although [[tritium|tritium's]] [[beta radiation]] is potentially dangerous if ingested, it has replaced radium in these applications. During the 1930s it was found that workers' exposure to radium by handling [[luminescence|luminescent]] paints caused serious health effects which included sores, [[anemia]] and [[bone cancer]]. This use of radium was stopped soon afterward. This is because radium is treated as [[calcium]] by the body, and deposited in the bones, where radioactivity degrades [[bone marrow|marrow]] and can mutate bone cells. The litigation and ultimate deaths of five "[[Radium Girls|Radium Girl]]" employees who had used radium-based [[luminous paint]]s on the dials of watches and clocks had a significant impact on the formulation of [[occupational disease]] [[labor law]]. Radium was also put in some foods for taste and as a preservative, but also exposed many people to radiation. Radium was once an additive in products like toothpaste, hair creams, and even food items due to its supposed curative powers. 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 ''[[Radithor]]''.) [[Destination spa|Spas]] featuring radium-rich water are still occasionally touted as beneficial, such as those in [[Misasa, Tottori]], [[Japan]]. Radium (usually in the form of [[radium chloride]]) is used in [[medicine]] to produce [[radon]] gas which in turn is used as a [[cancer]] treatment. The isotope {{SimpleNuclide|Radium|223}} is currently under investigation for use in [[medicine]] as [[cancer]] treatment of bone [[metastasis]]. == History == Radium ([[Latin]] ''radius'', ray) was [[discovery of the chemical elements|discovered]] by [[Marie Skłodowska-Curie]] and her husband [[Pierre Curie|Pierre]] in 1898 in pitchblende from North [[Bohemia]], in the Czech Republic (area around [[Jáchymov]]). While studying pitchblende the Curies removed [[uranium]] from it and found that the remaining material was still [[radioactive]]. They then separated out a radioactive mixture consisting mostly of [[barium]] which gave a brilliant green flame color and [[crimson|crimson carmine]] [[spectral line]]s which had never been documented before. The Curies announced their discovery to the [[French Academy of Sciences]] on [[26 December]] [[1898]]. In 1902, radium was isolated as a pure [[metal]] by Curie and [[André-Louis Debierne]] through the [[electrolysis]] of a pure radium [[chloride]] solution by using a [[mercury (element)|mercury]] [[cathode]] and [[distillation|distilling]] in an atmosphere of [[hydrogen]] gas. Historically the decay products of radium were known as radium A, B, C, etc. These are now known to be isotopes of other elements as follows: {| class="wikitable" |- | |Isotope |- |Radium emanation |<sup>222</sup>[[radon|Rn]] |- |Radium A |<sup>218</sup>[[polonium|Po]] |- |Radium B |<sup>214</sup>[[lead|Pb]] |- |Radium C |<sup>214</sup>[[bismuth|Bi]] |- |Radium C<sub>1</sub> |<sup>214</sup>Po |- |Radium C<sub>2</sub> |<sup>210</sup>[[thallium|Tl]] |- |Radium D |<sup>210</sup>Pb |- |Radium E |<sup>210</sup>Bi |- |Radium F |<sup>210</sup>Po |} On [[February 4]], [[1936]] radium E became the first [[radioactive]] element to be made synthetically. One unit for radioactivity, the non-[[SI]] [[curie]], is based on the radioactivity of <sup>226</sup>Ra (see [[Radioactivity]]). == Occurrence == Radium is a [[decay product]] of uranium and is therefore found in all uranium-bearing [[ore]]s. (One [[metric ton]] of pitchblende yields 0.0001 [[gram]]s of radium). Radium was originally acquired from [[uraninite|pitchblende]] ore from [[Jáchymov|Joachimsthal, Bohemia]], in the Czech Republic. [[Carnotite]] sands in [[Colorado]] provide some of the element, but richer ores are found in the [[Democratic Republic of the Congo]] and the [[Great Lakes (North America)|Great Lakes]] area of [[Canada]], and can also be extracted from uranium processing waste. Large radium-containing uranium deposits are located in Canada ([[Ontario]]), the United States ([[New Mexico]], [[Utah]], and [[Virginia]]), [[Australia]], and in other places. == Compounds == Its [[chemical compound|compound]]s color flames [[crimson|crimson carmine]] (rich red or crimson color with a shade of purple) and give a characteristic [[electromagnetic spectrum|spectrum]]. Due to its geologically short [[half life]] and intense radioactivity, radium compounds are quite rare, occurring almost exclusively in uranium ores. *[[radium fluoride]] (Ra[[fluorine|F]]<sub>2</sub>) *[[radium chloride]] (Ra[[chlorine|Cl]]<sub>2</sub>) *[[radium bromide]] (Ra[[bromine|Br]]<sub>2</sub>) *[[radium iodide]] (Ra[[iodine|I]]<sub>2</sub>) *[[radium oxide]] (Ra[[oxygen|O]]) *[[radium nitride]] (Ra<sub>3</sub>[[nitrogen|N]]<sub>2</sub>) ''See also [[:Category:Radium compounds|radium compounds]].'' == Isotopes == Radium (Ra) has 25 different known [[isotope]]s, four of which are found in nature, with <sup>226</sup>Ra being the most common. <sup>223</sup>Ra, <sup>224</sup>Ra, <sup>226</sup>Ra and <sup>228</sup>Ra are all generated naturally in the decay of either [[Uranium]] (U) or [[Thorium]] (Th). <sup>226</sup>Ra is a product of <sup>238</sup>U decay, and is the longest-lived isotope of radium with a [[half-life]] of 1602 years; next longest is <sup>228</sup>Ra, a product of <sup>232</sup>Th breakdown, with a half-life of 6.7 years. == Radioactivity == Radium is over one million times more radioactive than the same mass of [[uranium]]. Its decay occurs in at least seven stages; the successive main products have been studied and were called radium emanation or exradio (now identified as [[radon]]), radium A ([[polonium]]), radium B ([[lead]]), radium C ([[bismuth]]), etc. [[Radon]] is a heavy gas and the later products are solids. These products are themselves radioactive elements, each with an atomic weight a little lower than its predecessor. Radium loses about 1% of its activity in 25 years, being transformed into elements of lower atomic weight with [[lead]] being the final product of disintegration. The SI unit of radioactivity is the [[becquerel]] (Bq), equal to one disintegration per second. The [[curie]] is a non-SI unit defined as that amount of radioactivity which has the same disintegration rate as 1 gram of Ra-226 (3.7 x 10<sup>10</sup> disintegrations per second, or 37 GBq). ==Safety== Handling of radium has been blamed for [[Marie Curie]]'s premature death. *Radium is highly radioactive and its decay product, radon gas, is also radioactive. Since radium is chemically similar to calcium, it has the potential to cause great harm by replacing it in [[bone]]s. Inhalation, injection, ingestion or body exposure to radium can cause cancer and other disorders. Stored radium should be ventilated to prevent accumulation of radon. *Emitted energy from the decay of radium ionizes gases, affects photographic plates, causes sores on the skin, and produces many other detrimental effects. ==Further reading== * Scientific American (''Macklis RM, The great radium scandal. Sci.Am. 1993 Aug: 269(2):94-99'') * Clark, Claudia. (1987). ''Radium Girls: Women and Industrial Health Reform, 1910-1935''. University of North Carolina Press. ISBN 0-8078-4640-6. * Ken Silverstein, ''Harper's Magazine'', November 1998; The radioactive boy scout: when a teenager attempts to build a breeder reactor - case of David Hahn who managed to secure materials and equipment from businesses and information from government officials to develop an atomic energy radiation project for his Boy Scout merit-badge. * [[Decay chain]]s (with some examples including Radium) *[[Radium Girls]] ==References== * {{cite book|title=Guide to the Elements - Revised Edition|author=Albert Stwertka|publisher=Oxford University Press|date=1998|isbn=0-19-508083-1}} * {{cite web|url=http://periodic.lanl.gov/elements/88.html|title=Radium|publisher=Los Alamos National Laboratory (Chemistry Operations)|date=December 18, 2003|accessdate=2007-12-25}} * {{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=October 6, 1998|author=Denise Grady|accessdate=2007-12-25|publisher=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=2007-12-25}} ==External links== {{Commons|Radium}} {{wiktionary|radium}} * [http://www.webelements.com/webelements/elements/text/Ra/index.html WebElements.com - Radium] (also used as a reference) * [http://www.lateralscience.co.uk/radium/RaDisc.html Lateral Science - Radium Discovery] * [http://www.markwshead.com/stuffHappens/radium.html Photos of Radium Water Bath in Oklahoma] *[http://toxnet.nlm.nih.gov/cgi-bin/sis/search/r?dbs+hsdb:@term+@na+@rel+radium,+radioactive NLM Hazardous Substances Databank &ndash; Radium, Radioactive] {{clear}} {{Compact periodic table}} [[Category:Chemical elements]] [[Category:Alkaline earth metals]] [[Category:Radium|*]] [[als:Radium]] [[ar:راديوم]] [[bn:রেডিয়াম]] [[be:Радый]] [[bs:Radijum]] [[bg:Радий]] [[ca:Radi (element)]] [[cs:Radium]] [[co:Radiu]] [[da:Radium]] [[de:Radium]] [[et:Raadium]] [[el:Ράδιο]] [[es:Radio (elemento)]] [[eo:Radiumo]] [[eu:Erradio (elementua)]] [[fr:Radium]] [[fur:Radi]] [[gv:Raadjum]] [[gl:Radio (elemento)]] [[ko:라듐]] [[hy:Ռադիում]] [[hr:Radij]] [[io:Radiumo]] [[id:Radium]] [[ia:Radium]] [[is:Radín]] [[it:Radio (elemento)]] [[he:רדיום]] [[jv:Radium]] [[sw:Radi]] [[ht:Radyòm]] [[ku:Radyûm]] [[la:Radium]] [[lv:Rādijs]] [[lb:Radium]] [[lt:Radis]] [[jbo:dircyjinme]] [[hu:Rádium]] [[mk:Радиум]] [[ml:റേഡിയം]] [[mi:Konuruke]] [[nl:Radium]] [[ja:ラジウム]] [[no:Radium]] [[nn:Radium]] [[pl:Rad (pierwiastek)]] [[pt:Rádio (elemento químico)]] [[ro:Radiu]] [[ru:Радий]] [[scn:Ràdiu (elementu)]] [[simple:Radium]] [[sk:Rádium]] [[sl:Radij]] [[sr:Радијум]] [[sh:Radijum]] [[fi:Radium]] [[sv:Radium]] [[ta:ரேடியம்]] [[th:เรเดียม]] [[tr:Radyum]] [[uk:Радій]] [[zh:镭]]