Editing Polonium (section)

===Solid state form===
[[File:alpha po lattice.jpg|thumb|left|The alpha form of solid polonium]]
Polonium is a radioactive element that exists in two [[metal]]lic [[allotrope]]s. The alpha form is the only known example of a [[cubic (crystal system)|simple cubic]] crystal structure in a single atom basis at [[Standard temperature and pressure|STP]] ([[space group]] Pm{{overline|3}}m, no. 221). The unit cell has an edge length of 335.2 [[picometer]]s; the beta form is [[rhombohedral]].<ref>[[#Greenwood|Greenwood]], p. 753</ref><ref>{{cite book |first1=Gary L. |last1=Miessler |first2=Donald A. |last2=Tarr |title=Inorganic Chemistry |edition=3rd |page=[https://archive.org/details/inorganicchemist03edmies/page/285 285] |isbn=978-0-13-120198-9 |date=2004 |publisher=Pearson Prentice Hall |location=Upper Saddle River, N.J. |url=https://archive.org/details/inorganicchemist03edmies/page/285 }}</ref><ref>{{cite web| url = http://cst-www.nrl.navy.mil/lattice/struk/a_i.html| archive-url = https://web.archive.org/web/20010204004200/http://cst-www.nrl.navy.mil/lattice/struk/a_i.html| archive-date = 2001-02-04|date= 2000-11-20|work=Naval Research Laboratory |title = The beta Po (A_i) Structure| access-date = 2009-05-05}}</ref> The structure of polonium has been characterized by [[X-ray]] [[diffraction]]<ref>{{cite journal |last=Desando |first=R. J. |author2=Lange, R. C. |date=1966 |title=The structures of polonium and its compounds—I α and β polonium metal |journal=Journal of Inorganic and Nuclear Chemistry |volume=28 |issue=9 |pages=1837–1846 |doi=10.1016/0022-1902(66)80270-1}}</ref><ref>{{cite journal |last=Beamer |first=W. H. |author2=Maxwell, C. R. |date=1946 |title=The Crystal Structure of Polonium |journal=Journal of Chemical Physics |volume=14 |issue=9 |page=569 |doi=10.1063/1.1724201|hdl=2027/mdp.39015086430371 |hdl-access=free }}</ref> and [[electron diffraction]].<ref>{{cite journal |last1=Rollier |first1=M. A. |last2=Hendricks |first2=S. B.|last3= Maxwell|first3=L. R. |date=1936 |title=The Crystal Structure of Polonium by Electron Diffraction |journal=Journal of Chemical Physics |volume=4 |issue=10 |page=648 |doi=10.1063/1.1749762 |bibcode = 1936JChPh...4..648R|doi-access=free }}</ref>

<sup>210</sup>Po has the ability [[Volatility (chemistry)|to become airborne with ease]]: if a sample is heated in air to {{convert|55|C|F}}, 50% of it is vaporized in 45 hours to form [[diatomic molecule|diatomic]] Po<sub>2</sub> molecules, even though the melting point of polonium is {{convert|254|C|F}} and its boiling point is {{convert|962|C|F}}.<ref>{{cite journal| first1 = Bogdan |last1=Wąs| first2 = Ryszard |last2=Misiak| first3 = Mirosław |last3=Bartyzel| first4 = Barbara |last4=Petelenz | title = Thermochromatographic separation of <sup>206,208</sup>Po from a bismuth target bombarded with protons | journal =Nukleonika | date =2006| volume =51 | issue = Suppl. 2 | pages = s3–s5 | url =http://www.ichtj.waw.pl/ichtj/nukleon/back/full/vol51_2006/v51s2p03f.pdf}}</ref><ref name="CRC">{{RubberBible86th}}</ref><ref name="Thayer p78" />
More than one hypothesis exists for how polonium does this; one suggestion is that small clusters of polonium atoms are [[spallation|spalled off]] by the alpha decay.<ref>{{cite conference|title=Pseudo-evaporation of high specific activity alpha-emitting materials|author1= Condit, Ralph H.|author2=Gray, Leonard W.| author3=Mitchell, Mark A.|url=https://www.osti.gov/biblio/1162255| conference=EFCOG 2014 Safety Analysis Workshop|year=2014|publisher=Lawrence Livermore National Laboratory|osti= 1162255|conference-url=https://www.osti.gov/biblio/1169821}}</ref>