Editing Copernicium (section)

===Physical and atomic===
Copernicium should be a dense metal, with a [[density]] of 14.0&nbsp;g/cm<sup>3</sup> in the liquid state at 300&nbsp;K; this is similar to the known density of mercury, which is 13.534&nbsp;g/cm<sup>3</sup>. (Solid copernicium at the same temperature should have a higher density of 14.7&nbsp;g/cm<sup>3</sup>.) This results from the effects of copernicium's higher atomic weight being cancelled out by its larger interatomic distances compared to mercury.<ref name="CRNL" /> Some calculations predicted copernicium to be a gas at room temperature due to its closed-shell electron configuration,<ref name="Kratz">Kratz, Jens Volker. [https://tan11.jinr.ru/pdf/06_Sep/S_1/02_Kratz.pdf The Impact of Superheavy Elements on the Chemical and Physical Sciences] {{Webarchive|url=https://web.archive.org/web/20220614021708/http://tan11.jinr.ru/pdf/06_Sep/S_1/02_Kratz.pdf |date=14 June 2022 }}. 4th International Conference on the Chemistry and Physics of the Transactinide Elements, 5–11 September 2011, Sochi, Russia</ref> which would make it the first gaseous metal in the periodic table.<ref name="Haire" /><ref name="NS1975" /> A 2019 calculation agrees with these predictions on the role of relativistic effects, suggesting that copernicium will be a volatile liquid bound by [[dispersion forces]] under standard conditions. Its melting point is estimated at {{val|283|11|u=K}} and its boiling point at {{val|340|10|u=K}}, the latter in agreement with the experimentally estimated value of {{val|357|112|108|u=K}}.<ref name="CRNL" /> The atomic radius of copernicium is expected to be around 147&nbsp;pm. Due to the relativistic stabilization of the 7s orbital and destabilization of the 6d orbital, the Cn<sup>+</sup> and Cn<sup>2+</sup> ions are predicted to give up 6d electrons instead of 7s electrons, which is the opposite of the behavior of its lighter homologues.<ref name="Haire" />

In addition to the relativistic contraction and binding of the 7s subshell, the 6d<sub>5/2</sub> orbital is expected to be destabilized due to [[spin–orbit coupling]], making it behave similarly to the 7s orbital in terms of size, shape, and energy. Predictions of the expected band structure of copernicium are varied. Calculations in 2007 expected that copernicium may be a [[semiconductor]]<ref name="Eichler">{{cite journal |last1=Eichler |first1=R. |last2=Aksenov |first2=N. V. |last3=Belozerov |first3=A. V. |last4=Bozhikov |first4=G. A. |last5=Chepigin |first5=V. I. |last6=Dmitriev |first6=S. N. |last7=Dressler |first7=R. |last8=Gäggeler |first8=H. W. |last9=Gorshkov |first9=A. V. | display-authors=8 |date=2008 |title=Thermochemical and physical properties of element 112 |journal=[[Angewandte Chemie]] |volume=47 |issue=17 |pages=3262–3266 |doi=10.1002/anie.200705019 |pmid=18338360}}</ref> with a [[band gap]] of around 0.2&nbsp;[[electronvolt|eV]],<ref name="hcp">{{cite journal |last1=Gaston |first1=Nicola |last2=Opahle |first2=Ingo |last3=Gäggeler |first3=Heinz W. |last4=Schwerdtfeger |first4=Peter |date=2007 |title=Is eka-mercury (element 112) a group 12 metal? |url=https://www.researchgate.net/publication/51380328 |journal=[[Angewandte Chemie]] |volume=46 |issue=10 |pages=1663–1666 |doi=10.1002/anie.200604262 |pmid=17397075 |access-date=5 November 2013}}</ref> crystallizing in the [[hexagonal close-packed]] [[crystal structure]].<ref name="hcp" /> However, calculations in 2017 and 2018 suggested that copernicium should be a [[noble metal]] at standard conditions with a [[body-centered cubic]] crystal structure: it should hence have no band gap, like mercury, although the density of states at the [[Fermi level]] is expected to be lower for copernicium than for mercury.<ref name="bcc">{{cite journal |last1=Gyanchandani |first1=Jyoti |last2=Mishra |first2=Vinayak |first3=G. K. |last3=Dey |first4=S. K. |last4=Sikka |date=January 2018 |title=Super heavy element Copernicium: Cohesive and electronic properties revisited |url=https://www.sciencedirect.com/science/article/pii/S0038109817303344 |journal=Solid State Communications |volume=269 |pages=16–22 |doi=10.1016/j.ssc.2017.10.009 |bibcode=2018SSCom.269...16G |access-date=28 March 2018}}</ref><ref>{{cite journal |last1=Čenčariková |first1=Hana |last2=Legut |first2=Dominik |year=2018 |title=The effect of relativity on stability of Copernicium phases, their electronic structure and mechanical properties |journal=Physica B |volume=536 |pages=576–582 |doi=10.1016/j.physb.2017.11.035 |bibcode=2018PhyB..536..576C |arxiv=1810.01955|s2cid=119100368 }}</ref> 2019 calculations then suggested that in fact copernicium has a large band gap of 6.4 ± 0.2&nbsp;eV, which should be similar to that of the noble gas [[radon]] (predicted as 7.1&nbsp;eV) and would make it an insulator; bulk copernicium is predicted by these calculations to be bound mostly by [[dispersion force]]s, like the noble gases.<ref name="CRNL" /> Like mercury, radon, and flerovium, but not [[oganesson]] (eka-radon), copernicium is calculated to have no [[electron affinity]].<ref>{{cite web |url=https://www.kernchemie.uni-mainz.de/downloads/che_7/presentations/borschevsky.pdf |title=Fully relativistic ''ab initio'' studies of superheavy elements |last1=Borschevsky |first1=Anastasia |first2=Valeria |last2=Pershina |first3=Uzi |last3=Kaldor |first4=Ephraim |last4=Eliav |website=www.kernchemie.uni-mainz.de |publisher=[[Johannes Gutenberg University Mainz]] |access-date=15 January 2018 |url-status=dead |archive-url=https://web.archive.org/web/20180115184921/https://www.kernchemie.uni-mainz.de/downloads/che_7/presentations/borschevsky.pdf |archive-date=15 January 2018}}</ref>