Editing Oganesson (section)

===Calculated atomic and physical properties===
Oganesson is a member of [[noble gas|group 18]], the zero-[[valency (chemistry)|valence]] elements. The members of this group are usually inert to most common chemical reactions (for example, combustion) because the outer [[valence shell]] is completely filled with [[octet rule|eight electrons]]. This produces a stable, minimum energy configuration in which the outer electrons are tightly bound.<ref>{{cite web|last=Bader|first=Richard F.W|url=https://miranda.chemistry.mcmaster.ca/esam/|title=An Introduction to the Electronic Structure of Atoms and Molecules|publisher=McMaster University|access-date=18 January 2008|archive-date=12 October 2007|archive-url=https://web.archive.org/web/20071012213137/http://miranda.chemistry.mcmaster.ca/esam/|url-status=dead}}</ref> It is thought that similarly, oganesson has a [[closed shell|closed]] outer valence shell in which its [[valence electron]]s are arranged in a 7s<sup>2</sup>7p<sup>6</sup> [[electron configuration|configuration]].<ref name="Nash2005"/>

Consequently, some expect oganesson to have similar physical and chemical properties to other members of its group, most closely resembling the noble gas above it in the periodic table, [[radon]].<ref>{{cite web|url=https://lenntech.com/Periodic-chart-elements/Uuo-en.htm|title=Ununoctium (Uuo) – Chemical properties, Health and Environmental effects|publisher=Lenntech|access-date=18 January 2008|archive-url = https://web.archive.org/web/20080116172028/https://lenntech.com/Periodic-chart-elements/Uuo-en.htm |archive-date = 16 January 2008|url-status=dead}}</ref>
Following the [[periodic trend]], oganesson would be expected to be slightly more reactive than radon. However, theoretical calculations have shown that it could be significantly more reactive.<ref name="Kaldor"/> In addition to being far more reactive than radon, oganesson may be even more reactive than the elements [[flerovium]] and [[copernicium]], which are heavier homologs of the more chemically active elements [[lead]] and [[mercury (element)|mercury]], respectively.<ref name="Nash2005"/> The reason for the possible enhancement of the chemical activity of oganesson relative to radon is an energetic destabilization and a radial expansion of the last occupied 7p-[[Electron shell#Subshells|subshell]].<ref name="Nash2005"/> More precisely, considerable [[spin–orbit interaction]]s between the 7p electrons and the inert 7s electrons effectively lead to a second valence shell closing at [[flerovium]], and a significant decrease in stabilization of the closed shell of oganesson.<ref name="Nash2005"/> It has also been calculated that oganesson, unlike the other noble gases, binds an electron with release of energy, or in other words, it exhibits positive [[electron affinity]],<ref name="Pyykko">{{cite journal|title=QED corrections to the binding energy of the eka-radon (Z=118) negative ion|first1=Igor|last1=Goidenko|first2=Leonti|last2=Labzowsky|first3=Ephraim|last3=Eliav|first4=Uzi|last4=Kaldor|first5= Pekka |last5=Pyykkö|journal=Physical Review A|volume=67|date=2003|pages=020102(R)|doi=10.1103/PhysRevA.67.020102|bibcode = 2003PhRvA..67b0102G|issue=2}}</ref><ref>{{cite journal|volume=77|issue=27|journal=Physical Review Letters|date=1996|title=Element 118: The First Rare Gas with an Electron Affinity|first1=Ephraim |last1=Eliav |first2=Uzi |last2=Kaldor|doi=10.1103/PhysRevLett.77.5350|pages=5350–5352|pmid=10062781|last3=Ishikawa|first3=Y.|last4=Pyykkö|first4=P. |bibcode=1996PhRvL..77.5350E}}</ref> due to the relativistically stabilized 8s energy level and the destabilized 7p<sub>3/2</sub> level,<ref name="Landau">{{cite journal |last1=Landau |first1=Arie |last2=Eliav |first2=Ephraim |first3=Yasuyuki |last3=Ishikawa |first4=Uzi |last4=Kador |date=25 May 2001 |title=Benchmark calculations of electron affinities of the alkali atoms sodium to eka-francium (element 119) |url=https://www.researchgate.net/publication/234859102 |journal=Journal of Chemical Physics |volume=115 |issue=6 |pages=2389–92 |doi=10.1063/1.1386413 |access-date=15 September 2015|bibcode = 2001JChPh.115.2389L }}</ref> whereas copernicium and flerovium are predicted 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=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><ref>{{cite journal |last1=Borschevsky |first1=Anastasia |last2=Pershina |first2=Valeria |first3=Ephraim |last3=Eliav |first4=Uzi |last4=Kaldor |date=27 August 2009 |title=Electron affinity of element 114, with comparison to Sn and Pb |journal=Chemical Physics Letters |volume=480 |issue=1 |pages=49–51 |doi=10.1016/j.cplett.2009.08.059|bibcode=2009CPL...480...49B }}</ref> Nevertheless, [[quantum electrodynamic]] corrections have been shown to be quite significant in reducing this affinity by decreasing the binding in the [[anion]] Og<sup>−</sup> by 9%, thus confirming the importance of these corrections in [[superheavy element]]s.<ref name="Pyykko"/> 2022 calculations expect the electron affinity of oganesson to be 0.080(6)&nbsp;eV.<ref name=IPEA/>

[[Monte Carlo method|Monte Carlo simulations]] of oganesson's [[molecular dynamics]] predict it has a melting point of {{val|325|15|u=K}} and a boiling point of {{val|450|10|u=K}} due to [[relativistic quantum chemistry|relativistic effects]] (if these effects are ignored, oganesson would melt at ≈{{val|220|u=K}}). Thus oganesson would probably be a solid rather than a gas under [[standard conditions]], though still with a rather low melting point.<ref name="oganesson-melting"/><ref name="smits2020"/>

Oganesson is expected to have an extremely broad [[polarizability]], almost double that of radon.<ref name="Nash2005"/> Because of its tremendous polarizability, oganesson is expected to have an anomalously low first [[ionization energy]] of about 860&nbsp;kJ/mol, similar to that of [[cadmium]] and less than those of [[iridium]], [[platinum]], and [[gold]]. This is significantly smaller than the values predicted for [[darmstadtium]], [[roentgenium]], and copernicium, although it is greater than that predicted for flerovium.<ref>{{cite journal|journal=Journal of Physical Chemistry A| volume=1999| issue=3| pages=402–410|title=Spin-Orbit Effects, VSEPR Theory, and the Electronic Structures of Heavy and Superheavy Group IVA Hydrides and Group VIIIA Tetrafluorides. A Partial Role Reversal for Elements 114 and 118|first1=Clinton S.| last1=Nash| doi=10.1021/jp982735k| pmid=27676357| date=1999| last2=Bursten| first2=Bruce E.|bibcode=1999JPCA..103..402N}}</ref> Its second ionization energy should be around 1560&nbsp;kJ/mol.<ref name=IPEA/> Even the shell structure in the nucleus and electron cloud of oganesson is strongly impacted by relativistic effects: the valence and core electron subshells in oganesson are expected to be "smeared out" in a homogeneous [[Fermi gas]] of electrons, unlike those of the "less relativistic" radon and xenon (although there is some incipient delocalisation in radon), due to the very strong spin–orbit splitting of the 7p orbital in oganesson.<ref name="oganesson-elf"/> A similar effect for nucleons, particularly neutrons, is incipient in the closed-neutron-shell nucleus <sup>302</sup>Og and is strongly in force at the hypothetical superheavy closed-shell nucleus <sup>472</sup>164<!--YES IT REALLY IS STANDARD TO USE THE ATOMIC NUMBER HERE, THE CITED PAPER DOES IT TOO. IN PRACTICE SYSTEMATIC SYMBOLS ARE NOT USED THAT MUCH IN THE LITERATURE!-->, with 164 protons and 308 neutrons.<ref name="oganesson-elf">{{cite journal| journal=Phys. Rev. Lett.| volume=120| issue=5| page=053001| date=2018| title=Electron and Nucleon Localization Functions of Oganesson: Approaching the Thomas-Fermi Limit| first1=Paul |last1=Jerabek |first2=Bastian |last2=Schuetrumpf |first3=Peter |last3=Schwerdtfeger |first4=Witold |last4=Nazarewicz| doi=10.1103/PhysRevLett.120.053001| pmid=29481184| arxiv = 1707.08710 | bibcode = 2018PhRvL.120e3001J| s2cid=3575243}}</ref> Studies have also predicted that due to increasing electrostatic forces, oganesson may have a semibubble structure in proton density, having few protons at the center of its nucleus.<ref>{{Cite journal |last1=Schuetrumpf |first1=B. |last2=Nazarewicz |first2=W. |last3=Reinhard |first3=P.-G. |date=2017-08-11 |title=Central depression in nucleonic densities: Trend analysis in the nuclear density functional theory approach |url=https://link.aps.org/doi/10.1103/PhysRevC.96.024306 |journal=Physical Review C |volume=96 |issue=2 |pages=024306 |doi=10.1103/PhysRevC.96.024306|arxiv=1706.05759 |bibcode=2017PhRvC..96b4306S |s2cid=119510865 }}</ref><ref>{{Cite web |last=Garisto |first=Dan |date=12 February 2018 |title=5 ways the heaviest element on the periodic table is really bizarre |url=https://www.sciencenews.org/article/5-ways-heaviest-element-periodic-table-really-bizarre |access-date=2023-02-12 |website=ScienceNews |language=en-US}}</ref> Moreover, spin–orbit effects may cause bulk oganesson to be a [[semiconductor]], with a [[band gap]] of {{val|1.5|0.6}}&nbsp;eV predicted. All the lighter noble gases are [[Insulator (electricity)|insulators]] instead: for example, the band gap of bulk [[radon]] is expected to be {{val|7.1|0.5}}&nbsp;eV.<ref name="semiconductor">{{cite journal |last1=Mewes |first1=Jan-Michael |last2=Smits |first2=Odile Rosette |first3=Paul |last3=Jerabek |first4=Peter |last4=Schwerdtfeger |date=25 July 2019 |title=Oganesson is a Semiconductor: On the Relativistic Band-Gap Narrowing in the Heaviest Noble-Gas Solids |journal=Angewandte Chemie |volume=58 |issue=40 |pages=14260–14264 |doi=10.1002/anie.201908327 |pmid=31343819 |pmc=6790653 }}</ref>