Editing Copernicium (section)

===Chemical===
Copernicium is the tenth and last member of the 6d series and is the heaviest [[group 12 element]] in the periodic table, below [[zinc]], [[cadmium]] and [[mercury (element)|mercury]]. It is predicted to differ significantly from the lighter group&nbsp;12 elements. The valence s-[[Electron shell#Subshells|subshells]] of the group 12 elements and period 7 elements are expected to be relativistically contracted most strongly at copernicium. This and the closed-shell configuration of copernicium result in it probably being a very [[noble metal]]. A [[standard reduction potential]] of +2.1&nbsp;V is predicted for the Cn<sup>2+</sup>/Cn couple. Copernicium's predicted first ionization energy of 1155&nbsp;kJ/mol almost matches that of the noble gas [[xenon]] at 1170.4&nbsp;kJ/mol.<ref name="Haire" /> Copernicium's [[metallic bond]]s should also be very weak, possibly making it extremely volatile like the noble gases, and potentially making it gaseous at room temperature.<ref name="Haire" /><ref name="NS1975">"Chemistry on the islands of stability", ''New Scientist'', 11 September 1975, p. 574, {{ISSN|1032-1233}}</ref> However, it should be able to form metal–metal bonds with [[copper]], [[palladium]], [[platinum]], [[silver]], and [[gold]]; these bonds are predicted to be only about 15–20&nbsp;[[kilojoule per mole|kJ/mol]] weaker than the analogous bonds with mercury.<ref name="Haire" /> In opposition to the earlier suggestion,<ref name="Eliav1995">{{cite journal |last1=Pitzer |first1=K. S. |title=Are elements 112, 114, and 118 relatively inert gases? |journal=The Journal of Chemical Physics |volume=63 |issue=2 |pages=1032–1033 |year=1975 |doi=10.1063/1.431398 |url=https://escholarship.org/uc/item/2qw742ss |access-date=2019-07-08 |archive-date=2024-10-08 |archive-url=https://web.archive.org/web/20241008110131/https://escholarship.org/uc/item/2qw742ss |url-status=live }}</ref> ab initio calculations at the high level of accuracy<ref name="Mosyagin2006">{{cite journal |last1=Mosyagin |first1=N. S. |last2=Isaev |first2=T. A. |last3=Titov |first3=A. V. |title=Is E112 a relatively inert element? Benchmark relativistic correlation study of spectroscopic constants in E112H and its cation |journal=The Journal of Chemical Physics |volume=124 |issue=22 |pages=224302 |year=2006 |doi=10.1063/1.2206189 |pmid=16784269 |bibcode=2006JChPh.124v4302M |arxiv=physics/0508024|s2cid=119339584 }}</ref> predicted that the chemistry of singly-valent copernicium resembles that of mercury rather than that of the noble gases. The latter result can be explained by the huge [[spin–orbit interaction]] which significantly lowers the energy of the vacant 7p<sub>1/2</sub> state of copernicium.

Once copernicium is ionized, its chemistry may present several differences from those of zinc, cadmium, and mercury. Due to the stabilization of 7s electronic orbitals and destabilization of 6d ones caused by [[Relativistic quantum chemistry|relativistic effects]], Cn<sup>2+</sup> is likely to have a [Rn]5f<sup>14</sup>6d<sup>8</sup>7s<sup>2</sup> [[electronic configuration]], using the 6d orbitals before the 7s one, unlike its homologues. The fact that the 6d electrons participate more readily in chemical bonding means that once copernicium is ionized, it may behave more like a [[transition metal]] than its lighter [[Homologous series|homologues]], especially in the possible +4 oxidation state. In [[aqueous solution]]s, copernicium may form the +2 and perhaps +4 oxidation states.<ref name="Haire" /> The diatomic ion {{chem|Hg|2|2+}}, featuring mercury in the +1 oxidation state, is well-known, but the {{chem|Cn|2|2+}} ion is predicted to be unstable or even non-existent.<ref name="Haire" /> Copernicium(II) fluoride, CnF<sub>2</sub>, should be more unstable than the analogous mercury compound, [[mercury(II) fluoride]] (HgF<sub>2</sub>), and may even decompose spontaneously into its constituent elements. As the most electronegative reactive element, fluorine may be the only element able to oxidise copernicium even further to the +4 and even +6 oxidation states in CnF<sub>4</sub> and CnF<sub>6</sub>; the latter may require matrix-isolation conditions to be detected, as in the disputed detection of [[mercury(IV) fluoride|HgF<sub>4</sub>]]. CnF<sub>4</sub> should be more stable than CnF<sub>2</sub>.<ref name=VI>{{cite journal |last1=Hu |first1=Shu-Xian |last2=Zou |first2=Wenli |date=23 September 2021 |title=Stable copernicium hexafluoride (CnF<sub>6</sub>) with an oxidation state of VI+ |journal=Physical Chemistry Chemical Physics |volume=2022 |issue=24 |pages=321–325 |doi=10.1039/D1CP04360A|pmid=34889909 |bibcode=2021PCCP...24..321H }}</ref> In [[chemical polarity|polar]] solvents, copernicium is predicted to preferentially form the {{chem|CnF|5|-}} and {{chem|CnF|3|-}} anions rather than the analogous neutral fluorides (CnF<sub>4</sub> and CnF<sub>2</sub>, respectively), although the analogous bromide or iodide ions may be more stable towards [[hydrolysis]] in aqueous solution. The anions {{chem|CnCl|4|2-}} and {{chem|CnBr|4|2-}} should also be able to exist in aqueous solution.<ref name="Haire" /> The formation of thermodynamically stable copernicium(II) and (IV) fluorides would be analogous to the chemistry of xenon.<ref name="CRNL" /> Analogous to [[mercury(II) cyanide]] (Hg(CN)<sub>2</sub>), copernicium is expected to form a stable [[cyanide]], Cn(CN)<sub>2</sub>.<ref>{{cite journal |last1=Demissie |first1=Taye B. |last2=Ruud |first2=Kenneth |date=25 February 2017 |title=Darmstadtium, roentgenium, and copernicium form strong bonds with cyanide |journal=International Journal of Quantum Chemistry |volume=2017 |pages=e25393 |doi=10.1002/qua.25393|hdl=10037/13632|hdl-access=free }}</ref>