Editing Flerovium (section)

===Atomic and physical===
Flerovium is in group 14 in the [[periodic table]], below [[carbon]], [[silicon]], [[germanium]], [[tin]], and [[lead]]. Every previous group 14 element has 4 electrons in its valence shell, hence [[valence electron]] configuration ns<sup>2</sup>np<sup>2</sup>. For flerovium, the trend will continue and the valence electron configuration is predicted as 7s<sup>2</sup>7p<sup>2</sup>;<ref name="Haire" /> flerovium will be similar to its lighter [[congener (chemistry)|congeners]] in many ways. Differences are likely to arise; a large contributor is [[spin–orbit interaction|spin–orbit (SO) interaction]]—mutual interaction between the electrons' motion and [[Spin (physics)|spin]]. It is especially strong in superheavy elements, because the electrons move faster than in lighter atoms, at speeds comparable to the [[speed of light]].{{sfn|Thayer|2010|pp=63–64}} For flerovium, it lowers the 7s and the 7p electron energy levels<!--|level is an important word. Lv has no 8s electrons but they've been shown to affect its chem---> (stabilizing the corresponding electrons), but two of the 7p electron energy levels are stabilized more than the other four.<ref name="Faegri">
{{Cite journal
|last1=Faegri|first1=K.
|last2=Saue|first2=T.
|date=2001
|title=Diatomic molecules between very heavy elements of group 13 and group 17: A study of relativistic effects on bonding
|journal=[[Journal of Chemical Physics]]
|volume=115|issue=6|page=2456
|bibcode=2001JChPh.115.2456F
|doi=10.1063/1.1385366 
|doi-access=free
}}</ref> The stabilization of the 7s electrons is called the [[inert pair effect]], and the effect "tearing" the 7p subshell into the more and less stabilized parts is called subshell splitting. Computational chemists see the split as a change of the second ([[azimuthal quantum number|azimuthal]]) [[quantum number]] {{mvar|{{ell}}}} from 1 to {{frac|1|2}} and {{frac|3|2}} for the more stabilized and less stabilized parts of the 7p subshell, respectively.{{sfn|Thayer|2010|pp=63–67}}{{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.}} For many theoretical purposes, the valence electron configuration may be represented to reflect the 7p subshell split as 7s{{su|p=2|w=70%}}7p{{su|b=1/2|p=2|w=70%}}.<ref name="Haire" /> These effects cause flerovium's chemistry to be somewhat different from that of its lighter neighbours.

Because the spin–orbit splitting of the 7p subshell is very large in flerovium, and both of flerovium's filled orbitals in the 7th shell are stabilized relativistically; the valence electron configuration of flerovium may be considered to have a completely filled shell. Its first [[ionization energy]] of {{convert|8.539|eVpar|kJ/mol|abbr=on|lk=on}} should be the second-highest in group 14.<ref name="Haire" /> The 6d electron levels are also destabilized, leading to some early speculations that they may be chemically active, though newer work suggests this is unlikely.<ref name="Fricke1971" /> Because the first ionization energy is higher than in [[silicon]] and [[germanium]], though still lower than in [[carbon]], it has been suggested that flerovium could be classed as a [[metalloid]].<ref name="metalloid">{{cite journal|last1=Gong|first1=Sheng|last2=Wu|first2=Wei|first3=Fancy Qian|last3=Wang|first4=Jie|last4=Liu|first5=Yu|last5=Zhao|first6=Yiheng|last6=Shen|first7=Shuo|last7=Wang|first8=Qiang|last8=Sun|first9=Qian|last9=Wang|date=8 February 2019|title=Classifying superheavy elements by machine learning|journal=Physical Review A|volume=99|issue=2|pages=022110–1–7|doi=10.1103/PhysRevA.99.022110|bibcode=2019PhRvA..99b2110G|hdl=1721.1/120709|s2cid=126792685|hdl-access=free}}</ref>

Flerovium's closed-shell electron configuration means [[metallic bonding]] in metallic flerovium is weaker than in the elements before and after; so flerovium is expected to have a low [[boiling point]],<ref name="Haire" /> and has recently been suggested to be possibly a gaseous metal, similar to predictions for copernicium, which also has a closed-shell electron configuration.<ref name="Kratz" /> Flerovium's [[melting point|melting]] and boiling points were predicted in the 1970s to be around 70 and 150&nbsp;°C,<ref name="Haire" /> significantly lower than for the lighter group 14 elements (lead has 327 and 1749&nbsp;°C), and continuing the trend of decreasing boiling points down the group. Earlier studies predicted a boiling point of ~1000&nbsp;°C or 2840&nbsp;°C,<ref name="Fricke1971" /> but this is now considered unlikely because of the expected weak metallic bonding and that group trends would expect flerovium to have low sublimation enthalpy.<ref name="Haire" /> Preliminary 2021 calculations predicted that flerovium should have melting point −73&nbsp;°C (lower than mercury at −39&nbsp;°C and copernicium, predicted 10&nbsp;±&nbsp;11&nbsp;°C) and boiling point 107&nbsp;°C, which would make it a liquid metal.<ref name=liquid>{{cite journal|last1=Mewes|first1=Jan-Michael|last2=Schwerdtfeger|first2=Peter|date=11 February 2021|title=Exclusively Relativistic: Periodic Trends in the Melting and Boiling Points of Group 12|journal=Angewandte Chemie|volume= 60|issue= 14|pages= 7703–7709|doi=10.1002/anie.202100486|pmid=33576164|pmc=8048430}}</ref> Like [[mercury (element)|mercury]], [[radon]], and [[copernicium]], but not [[lead]] and [[oganesson]] (eka-radon), flerovium is calculated to have no [[electron affinity]].<ref>{{cite web|url=http://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|archive-url=https://web.archive.org/web/20180115184921/http://www.kernchemie.uni-mainz.de/downloads/che_7/presentations/borschevsky.pdf|archive-date=15 January 2018|url-status=dead|df=dmy-all}}</ref>

A 2010 study published calculations predicting a [[hexagonal close-packed]] crystal structure for flerovium due to spin–orbit coupling effects, and a density of 9.928&nbsp;g/cm<sup>3</sup>, though this was noted to be probably slightly too low.<ref name=hcp>{{cite journal|last1=Hermann|first1=Andreas|last2=Furthmüller|first2=Jürgen|first3=Heinz W.|last3=Gäggeler|first4=Peter|last4=Schwerdtfeger|date=2010|title=Spin-orbit effects in structural and electronic properties for the solid state of the group-14 elements from carbon to superheavy element 114|journal=Physical Review B|volume=82|issue=15|pages=155116–1–8|doi=10.1103/PhysRevB.82.155116|bibcode=2010PhRvB..82o5116H|url=https://www.dora.lib4ri.ch/psi/islandora/object/psi%3A15511}}</ref> Newer calculations published in 2017 expected flerovium to crystallize in [[face-centred cubic]] crystal structure like its lighter congener lead,<ref name=fcc>{{cite journal|last1=Maiz Hadj Ahmed|first1=H.|last2=Zaoui|first2=A.|last3=Ferhat|first3=M.|date=2017|title=Revisiting the ground state phase stability of super-heavy element Flerovium|journal=Cogent Physics|volume=4|issue=1|doi=10.1080/23311940.2017.1380454|bibcode=2017CogPh...4m8045M|s2cid=125920084|doi-access=free}}</ref> and calculations published in 2022 predicted a density of 11.4&nbsp;±&nbsp;0.3&nbsp;g/cm<sup>3</sup>, similar to lead (11.34&nbsp;g/cm<sup>3</sup>). These calculations found that the face-centred cubic and hexagonal close-packed structures should have nearly the same energy, a phenomenon reminiscent of the noble gases. These calculations predict that hexagonal close-packed flerovium should be a semiconductor, with a [[band gap]] of 0.8&nbsp;±&nbsp;0.3&nbsp;eV. (Copernicium is also predicted to be a semiconductor.) These calculations predict that the cohesive energy of flerovium should be around −0.5&nbsp;±&nbsp;0.1&nbsp;eV; this is similar to that predicted for oganesson (−0.45&nbsp;eV), larger than that predicted for copernicium (−0.38&nbsp;eV), but smaller than that of mercury (−0.79&nbsp;eV). The melting point was calculated as 284&nbsp;±&nbsp;50&nbsp;K (11&nbsp;±&nbsp;50&nbsp;°C), so that flerovium is probably a liquid at room temperature, although the boiling point was not determined.<ref name=Florez/>

The electron of a [[hydrogen-like atom|hydrogen-like]] flerovium ion (Fl<sup>113+</sup>; remove all but one electron) is expected to move so fast that its mass is 1.79 times that of a stationary electron, due to [[relativistic quantum chemistry|relativistic effects]]. (The figures for hydrogen-like lead and tin are expected to be 1.25 and 1.073 respectively.{{sfn|Thayer|2010|pp=64}}) Flerovium would form weaker metal–metal bonds than lead and would be [[adsorption|adsorbed]] less on surfaces.{{sfn|Thayer|2010|pp=64}}