Editing Unbinilium (section)

===Atomic and physical===
Being the second [[period 8 element]], unbinilium is predicted to be an alkaline earth metal, below [[beryllium]], [[magnesium]], [[calcium]], [[strontium]], [[barium]], and [[radium]]. Each of these elements has two [[valence electron]]s in the outermost s-orbital (valence electron configuration ''n''s<sup>2</sup>), which is easily lost in chemical reactions to form the +2 [[oxidation state]]: thus the alkaline earth metals are rather [[reactivity (chemistry)|reactive]] elements, with the exception of beryllium due to its small size. Unbinilium is predicted to continue the trend and have a valence electron configuration of 8s<sup>2</sup>. It is therefore expected to behave much like its lighter [[Congener (chemistry)|congeners]]; however, it is also predicted to differ from the lighter alkaline earth metals in some properties.<ref name="Haire" />

The main reason for the predicted differences between unbinilium and the other alkaline earth metals is the [[spin–orbit interaction|spin–orbit (SO) interaction]]—the mutual interaction between the electrons' motion and [[Spin (physics)|spin]]. The SO interaction is especially strong for the superheavy elements because their electrons move faster—at velocities comparable to the [[speed of light]]—than those in lighter atoms.<ref name="Thayer" /> In unbinilium atoms, it lowers the 7p and 8s electron energy levels,<!-- |level is an important word. Lv has no 8s electrons but they've been shown to affect its chemistry--> stabilizing the corresponding electrons, but two of the 7p electron energy levels are more stabilized than the other four.<ref name="Faegri">{{Cite journal | last1 = Fægri Jr. | first1 = Knut | last2 = Saue | first2 = Trond | doi = 10.1063/1.1385366 | title = Diatomic molecules between very heavy elements of group 13 and group 17: A study of relativistic effects on bonding | journal = The Journal of Chemical Physics | volume = 115 | issue = 6 | pages = 2456 | year = 2001 | publisher = American Institute of Physics |bibcode = 2001JChPh.115.2456F | doi-access = free }}</ref> The effect is called subshell splitting, as it splits the 7p subshell into more-stabilized and the less-stabilized parts. Computational chemists understand the split as a change of the second ([[azimuthal quantum number|azimuthal]]) [[quantum number]] ''l'' from 1 to 1/2 and 3/2 for the more-stabilized and less-stabilized parts of the 7p subshell, respectively.<ref name="Thayer" />{{efn|The quantum number corresponds to the letter in the electron orbital name: 0 to s, 1 to p, 2 to d, etc. See [[azimuthal quantum number]] for more information.}} Thus, the outer 8s electrons of unbinilium are stabilized and become harder to remove than expected, while the 7p<sub>3/2</sub> electrons are correspondingly destabilized, perhaps allowing them to participate in chemical reactions.<ref name="Haire" /> This stabilization of the outermost s-orbital (already significant in radium) is the key factor affecting unbinilium's chemistry, and causes all the trends for atomic and molecular properties of alkaline earth metals to reverse direction after barium.<ref name="Pershina">{{cite book |last=Pershina |first=Valeria |editor1-last=Schädel |editor1-first=Matthias |editor2-last=Shaughnessy |editor2-first=Dawn |chapter=Theoretical Chemistry of the Heaviest Elements |date=2014 |edition=2nd |title=The Chemistry of Superheavy Elements |publisher=Springer-Verlag |pages=204–7 |isbn=978-3-642-37465-4 |doi=10.1007/978-3-642-37466-1|s2cid=122675117 |chapter-url=https://cds.cern.ch/record/643991 }}</ref>

{| align="center"
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| valign=bottom | [[File:Atomic radius of alkali metals and alkaline earth metals.svg|class=skin-invert-image|thumb|none|upright=1.2|[[Empirical]] (Na–Cs, Mg–Ra) and predicted (Fr–Uhp, Ubn–Uhh) atomic radii of the alkali and alkaline earth metals from the [[period 3 element|third]] to the [[period 9 element|ninth period]], measured in [[angstrom]]s<ref name="Haire" /><ref name="pyykko" />]]
| [[File:Ionization energy of alkali metals and alkaline earth metals.svg|class=skin-invert-image|thumb|none|upright=1|Empirical (Na–Fr, Mg–Ra) and predicted (Uue–Uhp, Ubn–Uhh) ionization energy of the alkali and alkaline earth metals from the third to the ninth period, measured in electron volts<ref name="Haire" /><ref name="pyykko">{{Cite journal|last1=Pyykkö|first1=Pekka|title=A suggested periodic table up to Z ≤ 172, based on Dirac–Fock calculations on atoms and ions|journal=Physical Chemistry Chemical Physics|volume=13|issue=1|pages=161–8|date=2011|pmid=20967377|doi=10.1039/c0cp01575j|bibcode = 2011PCCP...13..161P }}</ref>]]
|}

Due to the stabilization of its outer 8s electrons, unbinilium's first [[ionization energy]]—the energy required to remove an electron from a neutral atom—is predicted to be 6.0&nbsp;eV, comparable to that of calcium.<ref name="Haire" /> The electron of the [[hydrogen-like atom|hydrogen-like]] unbinilium atom—oxidized so it has only one electron, Ubn<sup>119+</sup>—is predicted to move so quickly that its mass is 2.05 times that of a non-moving electron, a feature coming from the [[Relativistic quantum chemistry|relativistic effects]]. For comparison, the figure for hydrogen-like radium is 1.30 and the figure for hydrogen-like barium is 1.095.<ref name="Thayer" /> According to simple extrapolations of relativity laws, that indirectly indicates the contraction of the [[atomic radius]]<ref name="Thayer" /> to around 200&nbsp;[[picometer|pm]],<ref name="Haire" /> very close to that of strontium (215&nbsp;pm); the [[ionic radius]] of the Ubn<sup>2+</sup> ion is also correspondingly lowered to 160&nbsp;pm.<ref name="Haire" /> The trend in electron affinity is also expected to reverse direction similarly at radium and unbinilium.<ref name="Pershina" />

Unbinilium should be a [[solid]] at room temperature, with melting point 680&nbsp;°C:<ref name="BFricke">{{cite journal |last1=Fricke |first1=Burkhard |year=1975 |title=Superheavy elements: a prediction of their chemical and physical properties |journal=Recent Impact of Physics on Inorganic Chemistry |volume=21 |pages=[https://archive.org/details/recentimpactofph0000unse/page/89 89–144] |doi=10.1007/BFb0116498 |url=https://archive.org/details/recentimpactofph0000unse/page/89 |access-date=4 October 2013 |series=Structure and Bonding |isbn=978-3-540-07109-9 }}</ref> this continues the downward trend down the group, being lower than the value 700&nbsp;°C for radium.<ref>{{RubberBible86th}}</ref> The boiling point of unbinilium is expected to be around 1700&nbsp;°C, which is lower than that of all the previous elements in the group (in particular, radium boils at 1737&nbsp;°C), following the downward periodic trend.<ref name="Fricke1971" /> The density of unbinilium has been predicted to be 7&nbsp;g/cm<sup>3</sup>, continuing the trend of increasing density down the group: the value for radium is 5.5&nbsp;g/cm<sup>3</sup>.<ref name="Fricke1971" /><ref name="B&K" />