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{{Use Oxford spelling|date=July 2016}}
{{Use dmy dates|date=September 2015}}
{{Infobox flerovium|engvar=en-OED}}

'''Flerovium''' is a [[synthetic element|synthetic]] [[chemical element]]; it has [[Chemical symbol|symbol]] '''Fl''' and [[atomic number]] 114. It is an extremely [[radioactive]], [[Transactinide element|superheavy]] element, named after the Flerov Laboratory of Nuclear Reactions of the [[Joint Institute for Nuclear Research]] in [[Dubna]], Russia, where the element was discovered in 1999. The lab's name, in turn, honours Russian physicist [[Georgy Flyorov]] ({{lang|ru|Флёров|nocat=y}} in [[Cyrillic alphabet|Cyrillic]], hence the transliteration of "[[yo (Cyrillic)|yo]]" to "e"). [[International Union of Pure and Applied Chemistry|IUPAC]] adopted the name on 30 May 2012. The name and symbol had previously been proposed for element 102 ([[nobelium]]) but were not accepted by IUPAC at that time.

It is a transactinide in the [[p-block]] of the [[periodic table]]. It is in [[period 7 element|period 7]] and is the heaviest known member of the [[carbon group]]. Initial chemical studies in 2007–2008 indicated that flerovium was unexpectedly volatile for a group 14 element.<ref name="2009ex"/> More recent results show that flerovium's reaction with [[gold]] is similar to that of [[copernicium]], showing it is very [[volatility (chemistry)|volatile]] and may even be [[gas]]eous at [[standard temperature and pressure]]. Nonetheless, it also seems to show some [[metal]]lic properties, consistent with it being the heavier [[Homologous series|homologue]] of [[lead]].

Very little is known about flerovium, as it can only be produced one atom at a time, either through direct synthesis or through [[radioactive decay]] of even heavier elements, and all known isotopes are short-lived. Six [[isotopes of flerovium]] are known, ranging in [[mass number]] between 284 and 289; the most stable of these, {{chem2|^{289}Fl}}, has a [[half-life]] of ~2.1&nbsp;seconds, but the unconfirmed {{chem2|^{290}Fl}} may have a longer half-life of 19&nbsp;seconds, which would be one of the longest half-lives of any [[nuclide]] in these farthest reaches of the periodic table. Flerovium is predicted to be near the centre of the theorized [[island of stability]], and it is expected that heavier flerovium isotopes, especially the possibly [[magic number (physics)|magic]] {{chem2|^{298}Fl}}, may have even longer half-lives.

==Introduction==
{{Excerpt|Superheavy element|Introduction|subsections=yes}}

==History==
{{see also|Discovery of the chemical elements}}

===Pre-discovery===
In the late 1940s to early 1960s, the early days of making heavier and heavier [[transuranic element]]s, it was predicted that since such elements did not occur naturally, they would have shorter and shorter [[spontaneous fission]] half-lives, until they stopped existing altogether around element 108 (now called [[hassium]]). Initial work in synthesizing the heavier [[actinide]]s seemed to confirm this.<ref name="Sacks">{{cite news|last=Sacks|first=O.|date=8 February 2004|title=Greetings From the Island of Stability|newspaper=[[The New York Times]]}}</ref> But the [[nuclear shell model]], introduced in 1949 and extensively developed in the late 1960s by William Myers and [[Władysław Świątecki (physicist)|Władysław Świątecki]], stated that [[proton]]s and [[neutron]]s form shells within a nucleus, analogous to [[electron shell]]s. [[Noble gas]]es are [[reactivity (chemistry)|unreactive]] due to a full electron shell; similarly, it was theorized that elements with full nuclear shells – those having "[[magic number (physics)|magic]]" numbers of protons or neutrons – would be stabilized against [[radioactive decay|decay]]. A doubly magic [[isotope]], with magic numbers of both protons and neutrons, would be especially stabilized. Heiner Meldner calculated in 1965 that the next doubly magic isotope after [[lead-208|{{chem2|^{208}Pb}}]] was {{chem2|^{298}Fl}} with 114 protons and 184 neutrons, which would be the centre of an "[[island of stability]]".<ref name="Sacks" /><ref name="quest">{{cite journal|last1=Bemis|first1=C.E.|last2=Nix|first2=J.R.|date=1977|title=Superheavy elements - the quest in perspective|journal=Comments on Nuclear and Particle Physics|volume=7|issue=3|pages=65–78|url=http://inspirehep.net/record/1382449/files/v7-n3-p65.pdf|issn=0010-2709}}</ref> This island of stability, supposedly from [[copernicium]] (''Z''&nbsp;=&nbsp;112) to [[oganesson]] (''Z''&nbsp;=&nbsp;118), would come after a long "sea of instability" from [[mendelevium]] (''Z''&nbsp;=&nbsp;101) to [[roentgenium]] (''Z''&nbsp;=&nbsp;111),<ref name="Sacks" /> and the flerovium isotopes in it were speculated in 1966 to have half-lives over 10<sup>8</sup>&nbsp;years.<ref name="emsley">{{cite book|last=Emsley|first=John|title=Nature's Building Blocks: An A-Z Guide to the Elements|edition=New|date=2011|publisher=Oxford University Press|location=New York, NY|isbn=978-0-19-960563-7|page=580}}</ref> These early predictions fascinated researchers, and led to the first attempt to make flerovium, in 1968 with the reaction {{chem2|^{248}Cm(^{40}Ar,xn)}}. No flerovium atoms were detected; this was thought to be because the compound nucleus {{chem2|^{288}Fl}} only has 174 neutrons instead of the supposed magic 184, and this would have significant impact on the reaction [[cross section (physics)|cross section]] (yield) and half-lives of nuclei produced.<ref name="Transuraniumppl">{{cite book|last1=Hoffman|first1=D.C|last2=Ghiorso|first2=A.|last3=Seaborg|first3=G.T.|title=The Transuranium People: The Inside Story|publisher=Imperial College Press|date=2000|isbn=978-1-86094-087-3|bibcode=2000tpis.book.....H}}</ref><ref name="superlourds">{{cite journal|last1=Epherre|first1=M.|last2=Stephan|first2=C.|date=1975|title=Les éléments superlourds|language=fr|journal=Le Journal de Physique Colloques|volume=11|issue=36|pages=C5–159–164|url=https://core.ac.uk/download/pdf/46775464.pdf|doi=10.1051/jphyscol:1975541}}</ref> It was then 30 more years before flerovium was first made.<ref name="Sacks" /> Later work suggests the islands of stability around hassium and flerovium occur because these nuclei are respectively deformed and [[oblate spheroid|oblate]], which make them resistant to spontaneous fission, and that the true island of stability for spherical nuclei occurs at around [[unbibium]]-306 (122 protons, 184 neutrons).<ref name="Kratz"/><!--we can move this last sentence down later when we discuss the island of stability in greater detail-->

In the 1970s and 1980s, theoretical studies debated whether element 114 would be a more volatile metal like lead, or an inert gas.<ref name="tanm">{{cite web |last1=Gäggeler |first1=H. W. |date=5–7 November 2007 |title=Gas Phase Chemistry of Superheavy Elements |url=http://lch.web.psi.ch/files/lectures/TexasA&M/TexasA&M.pdf |archive-url=https://web.archive.org/web/20120220090755/http://lch.web.psi.ch/files/lectures/TexasA%26M/TexasA%26M.pdf |archive-date=20 February 2012 |access-date=10 August 2013 |publisher=[[Paul Scherrer Institute]] }}</ref>

===First signs===
The first sign of flerovium was found in December 1998 by a team of scientists at [[Joint Institute for Nuclear Research]] (JINR), [[Dubna]], Russia, led by [[Yuri Oganessian]], who bombarded a target of [[plutonium-244]] with accelerated nuclei of [[calcium-48]]:

:{{nuclide|plutonium|244}} + {{nuclide|calcium|48}} → {{nuclide|flerovium|292}}* → {{nuclide|flerovium|290}} + 2 {{nuclide|neutronium|1}}

This reaction had been tried before, without success; for this 1998 attempt, JINR had upgraded all of its equipment to detect and separate the produced atoms better and bombard the target more intensely.<ref name="Chapman">{{cite news|url=https://www.chemistryworld.com/what-it-takes-to-make-a-new-element/1017677.article|title= What it takes to make a new element|last=Chapman| first= Kit|date=November 30, 2016|magazine=Chemistry World|publisher= Royal Society of Chemistry|access-date=December 3, 2016}}</ref> One atom of flerovium, [[alpha decay]]ing with lifetime 30.4&nbsp;s, was detected. The [[decay energy]] measured was 9.71&nbsp;[[electronvolt|MeV]], giving an expected half-life of 2–23&nbsp;s.<ref name="99Og01" /> This observation was assigned to {{chem2|^{289}Fl}} and was published in January 1999.<ref name="99Og01">{{cite journal|last1=Oganessian
|first1=Yu. Ts.|display-authors=etal|date=1999|title=Synthesis of Superheavy Nuclei in the <sup>48</sup>Ca + <sup>244</sup>Pu Reaction|url=http://flerovlab.jinr.ru/linkc/flnr_presentations/articles/synthesis_of_Element_114_1999.pdf|journal=[[Physical Review Letters]]|volume=83|issue=16|page=3154|bibcode=1999PhRvL..83.3154O|doi=10.1103/PhysRevLett.83.3154|access-date=28 August 2013|archive-date=30 July 2020|archive-url=https://web.archive.org/web/20200730232521/http://flerovlab.jinr.ru/linkc/flnr_presentations/articles/synthesis_of_Element_114_1999.pdf}}</ref> The experiment was later repeated, but an isotope with these decay properties was never observed again, so the exact identity of this activity is unknown. It may have been due to the [[nuclear isomer|isomer]] {{chem2|^{289m}Fl}},<ref name="00Og01" /><ref name="04OgJINRPP">{{cite journal|last=Oganessian|first=Yu. Ts.|display-authors=etal|date=2004|title=Measurements of cross sections and decay properties of the isotopes of elements 112, 114, and 116 produced in the fusion reactions <sup>233,238</sup>U, <sup>242</sup>Pu, and <sup>248</sup>Cm + <sup>48</sup>Ca|url=http://www.jinr.ru/publish/Preprints/2004/160(E7-2004-160).pdf|journal=[[Physical Review C]]|volume=70|issue=6|article-number=064609|bibcode=2004PhRvC..70f4609O|doi=10.1103/PhysRevC.70.064609|archive-url=https://web.archive.org/web/20080528130343/http://www.jinr.ru/publish/Preprints/2004/160(E7-2004-160).pdf|archive-date=28 May 2008}}</ref> but because the presence of a whole series of longer-lived isomers in its decay chain would be rather doubtful, the most likely assignment of this chain is to the 2n channel leading to {{chem2|^{290}Fl}} and electron capture to {{chem2|^{290}Nh}}. This fits well with the systematics and trends of flerovium isotopes, and is consistent with the low beam energy chosen for that experiment, though further confirmation would be desirable via synthesis of {{chem2|^{294}Lv}} in a <sup>248</sup>Cm(<sup>48</sup>Ca,2n) reaction, which would alpha decay to {{chem2|^{290}Fl}}.<ref name="Hofmann2016" /> The [[RIKEN]] team reported possible synthesis of isotopes {{chem2|^{294}Lv}} and {{chem2|^{290}Fl}} in 2016 in a <sup>248</sup>Cm(<sup>48</sup>Ca,2n) reaction, but the alpha decay of {{chem2|^{294}Lv}} was missed, alpha decay of {{chem2|^{290}Fl}} to {{chem2|^{286}Cn}} was observed instead of electron capture to {{chem2|^{290}Nh}}, and the assignment to {{chem2|^{294}Lv}} instead of {{chem2|^{293}Lv}} was not certain.<ref name="Kaji" />

[[Glenn T. Seaborg]], a scientist at [[Lawrence Berkeley National Laboratory]] who had been involved in work to make such superheavy elements, had said in December 1997 that "one of his longest-lasting and most cherished dreams was to see one of these magic elements";<ref name="Sacks" /> he was told of the synthesis of flerovium by his colleague [[Albert Ghiorso]] soon after its publication in 1999. Ghiorso later recalled:<ref name="Seaborg-obituary" />

{{blockquote|I wanted Glenn to know, so I went to his bedside and told him. I thought I saw a gleam in his eye, but the next day when I went to visit him he didn't remember seeing me. As a scientist, he had died when he had that stroke.<ref name="Seaborg-obituary">{{cite news|last=Browne|first=M. W.|date=27 February 1999|title=Glenn Seaborg, Leader of Team That Found Plutonium, Dies at 86|url=https://www.nytimes.com/1999/02/27/us/glenn-seaborg-leader-of-team-that-found-plutonium-dies-at-86.html|access-date=26 August 2013|newspaper=[[The New York Times]]|archive-url=https://web.archive.org/web/20130522143152/http://www.nytimes.com/1999/02/27/us/glenn-seaborg-leader-of-team-that-found-plutonium-dies-at-86.html|archive-date=22 May 2013}}</ref>|Albert Ghiorso}}

Seaborg died two months later, on 25 February 1999.<ref name="Seaborg-obituary" />

In March 1999, the same team replaced the {{chem2|^{244}Pu}} target with {{chem2|^{242}Pu}} to make other flerovium isotopes. Two atoms of flerovium were produced as a result, each alpha-decaying with a half-life of 5.5 s. They were assigned as {{chem2|^{287}Fl}}.<ref name="99Og02">{{cite journal|last1=Oganessian|first1=Yu. Ts.|display-authors=etal|date=1999|title=Synthesis of nuclei of the superheavy element 114 in reactions induced by <sup>48</sup>Ca|journal=Nature|volume=400|issue=6741|page=242|bibcode=1999Natur.400..242O|doi=10.1038/22281|s2cid=4399615}}</ref> This activity has not been seen again either, and it is unclear what nucleus was produced. It is possible that it was an isomer <sup>287m</sup>Fl<ref name="04Og01" /> or from electron capture by <sup>287</sup>Fl, leading to <sup>287</sup>Nh and <sup>283</sup>Rg.<ref name="EXON1">{{cite conference|title=Remarks on the Fission Barriers of SHN and Search for Element 120|first1=S.|last1=Hofmann|first2=S.|last2=Heinz|first3=R.|last3=Mann|first4=J.|last4=Maurer|first5=G.|last5=Münzenberg|first6=S.|last6=Antalic|first7=W.|last7=Barth|first8=H. G.|last8=Burkhard|first9=L.|last9=Dahl|first10=K.|last10=Eberhardt|first11=R.|last11=Grzywacz|first12=J. H.|last12=Hamilton|first13=R. A.|last13=Henderson|first14=J. M.|last14=Kenneally|first15=B.|last15=Kindler|first16=I.|last16=Kojouharov|first17=R.|last17=Lang|first18=B.|last18=Lommel|first19=K.|last19=Miernik|first20=D.|last20=Miller|first21=K. J.|last21=Moody|first22=K.|last22=Morita|first23=K.|last23=Nishio|first24=A. G.|last24=Popeko|first25=J. B.|last25=Roberto|first26=J.|last26=Runke|first27=K. P.|last27=Rykaczewski|first28=S.|last28=Saro|first29=C.|last29=Schneidenberger|first30=H. J.|last30=Schött|first31=D. A.|last31=Shaughnessy|first32=M. A.|last32=Stoyer|first33=P.|last33=Thörle-Pospiech|first34=K.|last34=Tinschert|first35=N.|last35=Trautmann|first36=J.|last36=Uusitalo|first37=A. V.|last37=Yeremin|year=2016|conference=Exotic Nuclei|editor1-first=Yu. E.|editor1-last=Peninozhkevich|editor2-first=Yu. G.|editor2-last=Sobolev|book-title=Exotic Nuclei: EXON-2016 Proceedings of the International Symposium on Exotic Nuclei|pages=155–164|isbn=978-981-322-655-5}}</ref>

===Confirmed discovery===
The now-confirmed discovery of flerovium was made in June 1999 when the Dubna team repeated the first reaction from 1998. This time, two atoms of flerovium were produced; they alpha decayed with half-life 2.6&nbsp;s, different from the 1998 result.<ref name="00Og01">{{cite journal|last1=Oganessian|first1=Yu. Ts.|display-authors=etal|date=2000|title=Synthesis of superheavy nuclei in the <sup>48</sup>Ca + <sup>244</sup>Pu reaction: <sup>288</sup>114|journal=[[Physical Review C]]|volume=62|issue=4|article-number=041604|bibcode=2000PhRvC..62d1604O|doi=10.1103/PhysRevC.62.041604|url=https://cds.cern.ch/record/402957/files/SCAN-9910002.pdf?version=1}}</ref> This activity was initially assigned to <sup>288</sup>Fl in error, due to the confusion regarding the previous observations that were assumed to come from <sup>289</sup>Fl. Further work in December 2002 finally allowed a positive reassignment of the June 1999 atoms to <sup>289</sup>Fl.<ref name="04Og01">{{cite journal|last1=Oganessian|first1=Yu. Ts.|display-authors=etal|date=2004|title=Measurements of cross sections for the fusion-evaporation reactions <sup>244</sup>Pu(<sup>48</sup>Ca,xn)<sup>292−x</sup>114 and <sup>245</sup>Cm(<sup>48</sup>Ca,xn)<sup>293−x</sup>116|journal=[[Physical Review C]]|volume=69|issue=5|article-number=054607|bibcode=2004PhRvC..69e4607O|doi=10.1103/PhysRevC.69.054607|url=http://link.aps.org/abstract/PRC/V69/E054607/|doi-access=free}}</ref>

In May 2009, the Joint Working Party (JWP) of [[IUPAC]] published a report on the discovery of copernicium in which they acknowledged discovery of the isotope <sup>283</sup>Cn.<ref>{{cite journal|last1=Barber|first1=R. C.
|last2=Gäggeler|first2=H. W.
|last3=Karol|first3=P. J.
|last4=Nakahara|first4=H.
|last5=Vardaci|first5=E.
|last6=Vogt|first6=E.
|date=2009
|title=Discovery of the element with atomic number 112 (IUPAC Technical Report)
|journal=[[Pure and Applied Chemistry]]
|volume=81|page=1331|issue=7
|doi=10.1351/PAC-REP-08-03-05
|s2cid=95703833
|url=http://doc.rero.ch/record/297412/files/pac-rep-08-03-05.pdf
}}</ref> This implied the discovery of flerovium, from the acknowledgement of the data for the synthesis of <sup>287</sup>Fl and <sup>291</sup>[[livermorium|Lv]], which decay to <sup>283</sup>Cn. The discovery of flerovium-286 and -287 was confirmed in January 2009 at Berkeley. This was followed by confirmation of flerovium-288 and -289 in July 2009 at [[Gesellschaft für Schwerionenforschung]] (GSI) in Germany. In 2011, IUPAC evaluated the Dubna team's 1999–2007 experiments. They found the early data inconclusive, but accepted the results of 2004–2007 as flerovium, and the element was officially recognized as having been discovered.<ref name="jwr">{{cite journal|last1=Barber|first1=R. C.|last2=Karol|first2=P. J.|last3=Nakahara|first3=H.|last4=Vardaci|first4=E.|last5=Vogt|first5=E. W.|date=2011|title=Discovery of the elements with atomic numbers greater than or equal to 113 (IUPAC Technical Report)|journal=[[Pure and Applied Chemistry]]|volume=83|issue=7|page=1485|doi=10.1351/PAC-REP-10-05-01|doi-access=free}}</ref>

===Isotopes===
{{main|Isotopes of flerovium}}
{{Isotopes summary
|element=flerovium
|reaction ref=<ref name=thoennessen2016>{{Thoennessen2016|pages=229, 234, 238}}</ref>
|isotopes=
{{isotopes summary/isotope
|mn=284|sym=Fl|hl={{sort|0000025|2.5 ms}}|ref=<ref name="284Fl" />
|dm=SF, α|year=2015|re=<sup>240</sup>Pu(<sup>48</sup>Ca,4n)<br/><sup>239</sup>Pu(<sup>48</sup>Ca,3n)
}}
{{isotopes summary/isotope
|mn=285|sym=Fl|hl={{sort|00010|100 ms}}|ref=<ref name="PuCa2017" />
|dm=α|year=2010|re=<sup>242</sup>Pu(<sup>48</sup>Ca,5n)
}}
{{isotopes summary/isotope
|mn=286|sym=Fl|hl={{sort|000105|105 ms}}|ref=<ref name=PuCa2022/>
|dm=α, SF|year=2003|re=<sup>290</sup>Lv(—,α)
}}
{{isotopes summary/isotope
|mn=287|sym=Fl|hl={{sort|00036|360 ms}}|ref=<ref name=PuCa2022/>
|dm=α, EC?|year=2003|re=<sup>244</sup>Pu(<sup>48</sup>Ca,5n)}}
{{isotopes summary/isotope
|mn=288|sym=Fl|hl={{sort|00066|660 ms}}|ref=<ref name="shesummary" />
|dm=α|year=2004|re=<sup>244</sup>Pu(<sup>48</sup>Ca,4n)
}}
{{isotopes summary/isotope
|mn=289|sym=Fl|hl={{sort|0019|1.9 s}}|ref=<ref name="shesummary">{{cite journal|last=Oganessian|first=Y.T.|date=2015|title=Super-heavy element research|url=https://www.researchgate.net/publication/273327193|journal=Reports on Progress in Physics|volume=78|issue=3|article-number=036301|doi=10.1088/0034-4885/78/3/036301|pmid=25746203|bibcode=2015RPPh...78c6301O|s2cid=37779526}}</ref>
|dm=α|year=1999|re=<sup>244</sup>Pu(<sup>48</sup>Ca,3n)
}}
{{isotopes summary/isotope
|mn=289m|sym=Fl{{efn|name=nc|This isotope is unconfirmed}}|hl={{sort|0011|1.1 s}}|ref={{NUBASE2016|ref}}
|dm=α|year=2012|re=<sup>293m</sup>Lv(—,α)
}}
{{isotopes summary/isotope
|mn=290|sym=Fl{{efn|name=nc|This isotope is unconfirmed}}|hl={{sort|019|19 s}}|ref=<ref name="Hofmann2016" /><ref name="Kaji" />
|dm=α, EC?|year=1998|re=<sup>244</sup>Pu(<sup>48</sup>Ca,2n)
}}}}
While the method of chemical characterization of a daughter was successful for flerovium and livermorium, and the simpler structure of [[even–even nuclei]] made confirmation of oganesson (''Z''&nbsp;=&nbsp;118) straightforward, there have been difficulties in establishing the congruence of decay chains from isotopes with odd protons, odd neutrons, or both.<ref>{{cite journal|last1=Forsberg|first1=U.|last2=Rudolph|first2=D.|first3=C.|last3=Fahlander|first4=P.|last4=Golubev|first5=L. G.|last5=Sarmiento|first6=S.|last6=Åberg|first7=M.|last7=Block|first8=Ch. E.|last8=Düllmann|first9=F. P.|last9=Heßberger|first10=J. V.|last10=Kratz|first11=Alexander|last11=Yakushev|date=9 July 2016|title=A new assessment of the alleged link between element 115 and element 117 decay chains|url=http://portal.research.lu.se/portal/files/9762047/PhysLettB760_293_2016.pdf|journal=Physics Letters B|volume=760|issue=2016|pages=293–6|doi=10.1016/j.physletb.2016.07.008|access-date=2 April 2016|bibcode=2016PhLB..760..293F|doi-access=free}}</ref><ref>{{cite conference|url=http://www.epj-conferences.org/articles/epjconf/pdf/2016/26/epjconf-NS160-02003.pdf|title=Congruence of decay chains of elements 113, 115, and 117|last1=Forsberg|first1=Ulrika|last2=Fahlander|first2=Claes|last3=Rudolph|first3=Dirk|date=2016|conference=Nobel Symposium NS160 – Chemistry and Physics of Heavy and Superheavy Elements|doi=10.1051/epjconf/201613102003|doi-access=free}}</ref> To get around this problem with hot fusion, the decay chains from which terminate in spontaneous fission instead of connecting to known nuclei as cold fusion allows, experiments were done in Dubna in 2015 to produce lighter isotopes of flerovium by reaction of <sup>48</sup>Ca with <sup>239</sup>Pu and <sup>240</sup>Pu, particularly <sup>283</sup>Fl, <sup>284</sup>Fl, and <sup>285</sup>Fl; the last had previously been characterized in the <sup>242</sup>Pu(<sup>48</sup>Ca,5n)<sup>285</sup>Fl reaction at [[Lawrence Berkeley National Laboratory]] in 2010. <sup>285</sup>Fl was more clearly characterized, while the new isotope <sup>284</sup>Fl was found to undergo immediate spontaneous fission, and <sup>283</sup>Fl was not observed.<ref name="284Fl" /> This lightest isotope may yet conceivably be produced in the cold fusion reaction <sup>208</sup>Pb(<sup>76</sup>Ge,n)<sup>283</sup>Fl,<ref name="Hofmann2016" /> which the team at [[RIKEN]] in Japan at one point considered investigating:<ref name="morita">{{cite journal|url=https://www.mi.infn.it/~bracco/italia-giappone-talks/morita.pdf|title=Research on Superheavy Elements at RIKEN|last=Morita|first=Kōsuke|journal=APS Division of Nuclear Physics Meeting Abstracts|volume=2014|pages=DG.002|access-date=28 April 2017|bibcode=2014APS..DNP.DG002M|year=2014}}</ref><ref name="morimoto">{{cite web|url=http://www.kernchemie.uni-mainz.de/downloads/che_7/presentations/morimoto.pdf|title=Production and Decay Properties of <sup>266</sup>Bh and its daughter nuclei by using the <sup>248</sup>Cm(<sup>23</sup>Na,5n)<sup>266</sup>Bh Reaction|last=Morimoto|first=Kouji|date=October 2009|website=www.kernchemie.uni-mainz.de|publisher=[[University of Mainz]]|access-date=28 April 2017|archive-url=https://web.archive.org/web/20170921193318/http://www.kernchemie.uni-mainz.de/downloads/che_7/presentations/morimoto.pdf|archive-date=21 September 2017}}</ref> this reaction is expected to have a higher cross-section of 200&nbsp;fb than the "world record" low of 30&nbsp;fb for <sup>209</sup>Bi(<sup>70</sup>Zn,n)<sup>278</sup>Nh, the reaction which RIKEN used for the official discovery of element 113 ([[nihonium]]).<ref name="Hofmann2016" /><ref name="Zagrebaev" /><ref>{{cite web|url=http://cyclotron.tamu.edu/she2015/assets/pdfs/presentations/Heinz_SHE_2015_TAMU.pdf|title=Probing the Stability of Superheavy Nuclei with Radioactive Ion Beams|last=Heinz|first=Sophie|date=1 April 2015|website=cyclotron.tamu.edu|publisher=Texas A & M University|access-date=30 April 2017}}</ref> Alternatively, it might be produced in future as a great-granddaughter of <sup>295</sup>[[unbinilium|120]], reachable in the <sup>249</sup>Cf(<sup>50</sup>Ti,4n) reaction.<ref name=jinr2024>{{Cite web |url=https://indico.jinr.ru/event/4343/contributions/28663/attachments/20748/36083/U%20+%20Cr%20AYSS%202024.pptx |title=Synthesis and study of the decay properties of isotopes of superheavy element Lv in Reactions <sup>238</sup>U + <sup>54</sup>Cr and <sup>242</sup>Pu + <sup>50</sup>Ti |last=Ibadullayev |first=Dastan |date=2024 |website=jinr.ru |publisher=[[Joint Institute for Nuclear Research]] |access-date=2 November 2024 |quote=}}</ref> The reaction <sup>239</sup>Pu+<sup>48</sup>Ca has also been suggested as a means to produce <sup>282</sup>Fl and <sup>283</sup>Fl in the 5n and 4n channels respectively, but so far only the 3n channel leading to <sup>284</sup>Fl has been observed.<ref name=Zagrebaev/>

The Dubna team repeated their investigation of the <sup>240</sup>Pu+<sup>48</sup>Ca reaction in 2017, observing three new consistent decay chains of <sup>285</sup>Fl, another decay chain from this nuclide that may pass through some isomeric states in its daughters, a chain that could be assigned to <sup>287</sup>Fl (likely from <sup>242</sup>Pu impurities in the target), and some spontaneous fissions of which some could be from <sup>284</sup>Fl, though other interpretations including side reactions involving evaporation of charged particles are also possible.<ref name="PuCa2017" /> The alpha decay of <sup>284</sup>Fl to spontaneously fissioning <sup>280</sup>Cn was finally observed by the Dubna team in 2024.<ref name=jinr2024/>

===Naming===
[[File:RUSMARKA-1660.jpg|thumb|right|Stamp of Russia, issued in 2013, dedicated to [[Georgy Flyorov]] and flerovium]]
Per [[Mendeleev's predicted elements|Mendeleev's nomenclature for unnamed and undiscovered elements]], flerovium is sometimes called ''eka-[[lead]]''. In 1979, IUPAC published recommendations according to which the element was to be called ''ununquadium'' (symbol ''Uuq''),<ref name="iupac">
{{cite journal
|last=Chatt|first=J.
|date=1979
|title=Recommendations for the naming of elements of atomic numbers greater than 100
|journal=[[Pure and Applied Chemistry]]
|volume=51|issue=2|pages=381–384
|doi=10.1351/pac197951020381
|doi-access=free
}}</ref> a [[systematic element name]] as a [[placeholder name|placeholder]], until the discovery of the element is confirmed and a permanent name is decided on. Most scientists in the field called it "element 114", with the symbol of ''E114'', ''(114)'' or ''114''.<ref name="Haire" />

Per IUPAC recommendations, the discoverer(s) of a new element has the right to suggest a name.<ref>
{{cite journal
|last=Koppenol|first=W. H.
|date=2002
|title=Naming of new elements (IUPAC Recommendations 2002)
|url=http://media.iupac.org/publications/pac/2002/pdf/7405x0787.pdf
|journal=[[Pure and Applied Chemistry]]
|volume=74|page=787|issue=5
|doi=10.1351/pac200274050787
|s2cid=95859397
}}</ref>
After IUPAC recognized the discovery of flerovium and livermorium on 1 June 2011, IUPAC asked the discovery team at JINR to suggest permanent names for the two elements. The Dubna team chose the name ''flerovium'' (symbol Fl),<ref>
{{cite news
|last= Brown|first=M.
|date=6 June 2011
|title=Two Ultraheavy Elements Added to Periodic Table
|url=https://www.wired.com/wiredscience/2011/06/new-heavy-elements/#more-62779
|magazine=[[Wired (magazine)|Wired]]
|access-date=7 June 2011
}}</ref><ref name="livesc">
{{cite web
|last=Welsh|first=J.
|date=2 December 2011
|title=Two Elements Named: Livermorium and Flerovium
|url=http://www.livescience.com/17287-element-names-flerovium-livermorium.html
|website=[[LiveScience]]
|access-date=2 December 2011
}}</ref> after Russia's [[Flerov Laboratory of Nuclear Reactions]] (FLNR), named after Soviet physicist [[Georgy Flyorov]] (also spelled Flerov); earlier reports claim the element name was directly proposed to honour Flyorov.<ref name="E114&116">
{{cite web
|publisher=[[RIA Novosti]]
|date=26 March 2011
|access-date=8 May 2011
|url=http://www.rian.ru/science/20110326/358081075.html
|title=Российские физики предложат назвать 116 химический элемент московием
|trans-title=Russian physicists have offered to call 116 chemical element ''moscovium''
}} Mikhail Itkis, the vice-director of JINR, stated: "We would like to name element 114 after [[Georgy Flerov]] – flerovium, and the second [element 116] – moscovium, not after Moscow, but after [[Moscow Oblast]]".</ref> In accordance with the proposal received from the discoverers, IUPAC officially named flerovium after Flerov Laboratory of Nuclear Reactions, not after Flyorov himself.<ref name="IUPAC-names-114-116" /> Flyorov is known for writing to [[Joseph Stalin]] in April 1942 and pointing out the silence in scientific journals in the field of [[nuclear fission]] in the United States, Great Britain, and Germany. Flyorov deduced that this research must have become [[classified information]] in those countries. Flyorov's work and urgings led to the development of the USSR's own [[Soviet atomic bomb project|atomic bomb project]].<ref name="livesc" /> Flyorov is also known for the discovery of [[spontaneous fission]] with [[Konstantin Petrzhak]]. The naming ceremony for flerovium and livermorium was held on 24 October 2012 in Moscow.<ref>{{cite web|url=http://newuc.jinr.ru/img_sections/file/Practice2016/EU/2016-07%20AGP_SHE.pdf|title=Synthesis of superheavy elements|last=Popeko|first=Andrey G.|date=2016|website=jinr.ru|publisher=[[Joint Institute for Nuclear Research]]|access-date=4 February 2018|archive-date=4 February 2018|archive-url=https://web.archive.org/web/20180204124109/http://newuc.jinr.ru/img_sections/file/Practice2016/EU/2016-07%20AGP_SHE.pdf}}</ref>

In a 2015 interview with Oganessian, the host, in preparation to ask a question, said, "You said you had dreamed to name [an element] after your teacher Georgy Flyorov." Without letting the host finish, Oganessian repeatedly said, "I did."<ref name="OTR">{{Cite interview|last=Oganessian|first=Yu. Ts.|interviewer-last=Orlova|interviewer-first=O.|title=Гамбургский счет|trans-title=Hamburg reckoning|date=2015-10-10|access-date=2020-01-18|url=https://www.youtube.com/watch?v=ZdnvOxxDeKM| archive-url=https://ghostarchive.org/varchive/youtube/20211117/ZdnvOxxDeKM| archive-date=2021-11-17| url-status=live|language=ru|publisher=[[Public Television of Russia]]}}{{cbignore}}</ref>
{{clear}}

==Predicted properties==
Very few properties of flerovium or its compounds have been measured; due to its extremely limited and expensive production<ref name="Superheavy element Bloomberg"/> and the fact that it decays very quickly. A few singular properties have been measured, but for the most part, properties of flerovium remain unknown and only predictions are available.

===Nuclear stability and isotopes===
{{main|Isotopes of flerovium}}
[[File:IBA nuclear shells.svg|thumb|right|upright=1.6|Regions of differently shaped nuclei, as predicted by the [[interacting boson model]]<ref name="Kratz" />]]
The basis of the chemical [[periodic trends|periodicity]] in the periodic table is the electron shell closure at each noble gas ([[atomic number]]s [[helium|2]], [[neon|10]], [[argon|18]], [[krypton|36]], [[xenon|54]], [[radon|86]], and [[oganesson|118]]): as any further electrons must enter a new shell with higher energy, closed-shell electron configurations are markedly more stable, hence the inertness of noble gases.<ref name="Fricke1971" /> Protons and neutrons are also known to form closed nuclear shells, so the same happens at nucleon shell closures, which happen at specific nucleon numbers often dubbed "magic numbers". The known magic numbers are 2, 8, 20, 28, 50, and 82 for protons and neutrons; also 126 for neutrons.<ref name="Fricke1971" /> Nuclei with magic proton and [[neutron number]]s, such as [[helium-4]], [[oxygen-16]], [[calcium-48]], and [[lead-208]], are "doubly magic" and are very stable. This stability is very important for [[superheavy element]]s: with no stabilization, half-lives would be expected by exponential extrapolation to be [[nanosecond]]s at [[darmstadtium]] (element 110), because the ever-increasing electrostatic repulsion between protons overcomes the limited-range [[strong nuclear force]] that holds nuclei together. The next closed nucleon shells (magic numbers) are thought to denote the centre of the long-sought island of stability, where half-lives to alpha decay and spontaneous fission lengthen again.<ref name="Fricke1971" />

[[File:Next proton shell.svg|thumb|right|upright=1.6|Orbitals with high [[azimuthal quantum number]] are raised in energy, eliminating what would otherwise be a gap in orbital energy corresponding to a closed proton shell at element 114. This raises the next proton shell to the region around [[unbinilium|element 120]].<ref name="Kratz" />]]
Initially, by analogy with neutron magic number 126, the next proton shell was also expected at [[unbihexium|element 126]], too far beyond the synthesis capabilities of the mid-20th century to get much theoretical attention. In 1966, new values for the potential and [[spin–orbit interaction]] in this region of the periodic table<ref>{{Cite book|last1=Kalinkin|first1=B. N.|last2=Gareev|first2=F. A.|arxiv=nucl-th/0111083v2|title=Synthesis of Superheavy elements and Theory of Atomic Nucleus|date=2001|doi=10.1142/9789812777300_0009|journal=Exotic Nuclei|page=118|isbn=978-981-238-025-8|bibcode=2002exnu.conf..118K|citeseerx=10.1.1.264.7426|s2cid=119481840}}</ref> contradicted this and predicted that the next proton shell would instead be at element 114,<ref name="Fricke1971" /> and that nuclei in this region would be relatively stable against spontaneous fission.<ref name="Fricke1971" /> The expected closed neutron shells in this region were at neutron number 184 or 196, making <sup>298</sup>Fl and <sup>310</sup>Fl candidates for being doubly magic.<ref name="Fricke1971" /> 1972 estimates predicted a half-life of around 1&nbsp;year for <sup>298</sup>Fl, which was expected to be near an [[island of stability]] centered near <sup>294</sup>Ds (with a half-life around 10<sup>10</sup>&nbsp;years, comparable to <sup>232</sup>[[thorium|Th]]).<ref name="Fricke1971" /> After making the first isotopes of elements 112–118 at the turn of the 21st century, it was found that these neutron-deficient isotopes were stabilized against fission. In 2008 it was thus hypothesized that the stabilization against fission of these nuclides was due to their [[Spheroid|oblate]] nuclei, and that a region of oblate nuclei was centred on <sup>288</sup>Fl. Also, new theoretical models showed that the expected energy gap between the proton orbitals 2f<sub>7/2</sub> (filled at element 114) and 2f<sub>5/2</sub> (filled at [[unbinilium|element 120]]) was smaller than expected, so element 114 no longer appeared to be a stable spherical closed nuclear shell. The next doubly magic nucleus is now expected to be around <sup>306</sup>Ubb, but this nuclide's expected short half-life and low production [[cross section (physics)|cross section]] make its synthesis challenging.<ref name="Kratz" /> Still, the island of stability is expected to exist in this region, and nearer its centre (which has not been approached closely enough yet) some nuclides, such as <sup>291</sup>[[moscovium|Mc]] and its alpha- and beta-decay [[decay product|daughters]],{{efn|Specifically, <sup>291</sup>Mc, <sup>291</sup>Fl, <sup>291</sup>Nh, <sup>287</sup>Nh, <sup>287</sup>Cn, <sup>287</sup>Rg, <sup>283</sup>Rg, and <sup>283</sup>Ds, which are expected to decay to the relatively longer-lived nuclei <sup>283</sup>Mt, <sup>287</sup>Ds, and <sup>291</sup>Cn.<ref name="Zagrebaev" />}} may be found to decay by [[positron emission]] or [[electron capture]] and thus move into the centre of the island.<ref name="Zagrebaev">{{cite conference|last1=Zagrebaev|first1=Valeriy|last2=Karpov|first2=Alexander|last3=Greiner|first3=Walter|date=2013|title=Future of superheavy element research: Which nuclei could be synthesized within the next few years?|publisher=IOP Science|book-title=Journal of Physics: Conference Series|volume=420|pages=1–15|url=http://iopscience.iop.org/1742-6596/420/1/012001/pdf/1742-6596_420_1_012001.pdf|access-date=20 August 2013}}</ref> Due to the expected high fission barriers, any nucleus in this island of stability would decay exclusively by alpha decay and perhaps some electron capture and [[beta decay]],<ref name="Fricke1971" /> both of which would bring the nuclei closer to the beta-stability line where the island is expected to be. Electron capture is needed to reach the island, which is problematic because it is not certain that electron capture is a major decay mode in this region of the [[chart of nuclides]].<ref name="Zagrebaev" />

Experiments were done in 2000–2004 at Flerov Laboratory of Nuclear Reactions in Dubna studying the fission properties of the compound nucleus <sup>292</sup>Fl by bombarding <sup>244</sup>Pu with accelerated <sup>48</sup>Ca ions.<ref name="jinr20006" /> A compound nucleus is a loose combination of [[nucleon]]s that have not yet arranged themselves into nuclear shells. It has no internal structure and is held together only by the collision forces between the two nuclei.<ref name="compoundnucleus" />{{efn|It is estimated that it requires around 10<sup>−14</sup>&nbsp;s for the nucleons to arrange themselves into nuclear shells, at which point the compound nucleus becomes a [[nuclide]], and this number is used by IUPAC as the minimum half-life a claimed isotope must have to be recognized as a nuclide.<ref name="compoundnucleus">{{cite book|last=Emsley|first=John|title=Nature's Building Blocks: An A-Z Guide to the Elements|edition=New|date=2011|publisher=Oxford University Press|location=New York, NY|isbn=978-0-19-960563-7|page=590}}</ref>}} Results showed how such nuclei fission mainly by expelling doubly magic or nearly doubly magic fragments such as <sup>40</sup>[[calcium|Ca]], <sup>132</sup>[[tin|Sn]], <sup>208</sup>[[lead|Pb]], or <sup>209</sup>[[bismuth|Bi]]. It was also found that <sup>48</sup>Ca and <sup>58</sup>[[iron|Fe]] projectiles had a similar yield for the fusion-fission pathway, suggesting possible future use of <sup>58</sup>Fe projectiles in making superheavy elements.<ref name="jinr20006">
{{cite web
|title=JINR Annual Reports 2000–2006
|url=http://www1.jinr.ru/Reports/Reports_eng_arh.html
|publisher=[[Joint Institute for Nuclear Research|JINR]]
|access-date=27 August 2013
}}</ref> It has also been suggested that a neutron-rich flerovium isotope can be formed by quasifission (partial fusion followed by fission) of a massive nucleus.<ref name="ZG" /> Recently it has been shown that multi-nucleon transfer reactions in collisions of actinide nuclei (such as [[uranium]] and [[curium]]) might be used to make neutron-rich superheavy nuclei in the island of stability,<ref name="ZG">
{{cite journal
|last1=Zagrebaev|first1=V.
|last2=Greiner|first2=W.
|year=2008
|title=Synthesis of superheavy nuclei: A search for new production reactions
|journal=[[Physical Review C]]
|volume=78|issue=3|article-number=034610
|arxiv=0807.2537
|bibcode=2008PhRvC..78c4610Z
|doi=10.1103/PhysRevC.78.034610
}}</ref> though production of neutron-rich [[nobelium]] or [[seaborgium]] is more likely.<ref name="Zagrebaev" />

Theoretical estimates of alpha decay half-lives of flerovium isotopes, support the experimental data.<ref name="half-lifes">
{{cite journal
|last1=Chowdhury|first1=P. R.
|last2=Samanta|first2=C.
|last3=Basu|first3=D. N.
|date=2006
|title=α decay half-lives of new superheavy elements
|journal=[[Physical Review C]]
|volume=73|issue=1|article-number=014612
|arxiv=nucl-th/0507054
|bibcode=2006PhRvC..73a4612C
|doi=10.1103/PhysRevC.73.014612
|s2cid=118739116
}}</ref><ref>
{{cite journal
|last1=Samanta|first1=C.
|last2=Chowdhury|first2=P. R.
|last3=Basu|first3=D. N.
|year=2007
|title=Predictions of alpha decay half lives of heavy and superheavy elements
|journal=[[Nuclear Physics A]]
|volume=789|issue=1–4|pages=142–154
|arxiv=nucl-th/0703086
|bibcode=2007NuPhA.789..142S
|doi=10.1016/j.nuclphysa.2007.04.001
|citeseerx=10.1.1.264.8177
|s2cid=7496348
}}</ref>
The fission-survived isotope <sup>298</sup>Fl, long expected to be doubly magic, is predicted to have alpha decay half-life ~17 days.<ref name="prc08">
{{cite journal
|last1=Chowdhury|first1=P. R.
|last2=Samanta|first2=C.
|last3=Basu|first3=D. N.
|year=2008
|title=Search for long lived heaviest nuclei beyond the valley of stability
|journal=[[Physical Review C]]
|volume=77|issue=4|article-number=044603
|arxiv=0802.3837
|bibcode=2008PhRvC..77d4603C
|doi=10.1103/PhysRevC.77.044603
|s2cid=119207807
}}</ref><ref>
{{cite journal
|last1=Roy Chowdhury|first1=P.
|last2=Samanta|first2=C.
|last3=Basu|first3=D. N.
|year=2008
|title=Nuclear half-lives for α-radioactivity of elements with 100 ≤ Z ≤ 130
|journal=[[Atomic Data and Nuclear Data Tables]]
|volume=94|issue=6|pages=781–806
|arxiv=0802.4161
|bibcode=2008ADNDT..94..781C
|doi=10.1016/j.adt.2008.01.003
|s2cid=96718440
}}</ref> Making <sup>298</sup>Fl directly by a fusion–evaporation pathway is currently impossible: no known combination of target and stable projectile can give 184 neutrons for the compound nucleus, and radioactive projectiles such as <sup>50</sup>Ca (half-life 14&nbsp;s) cannot yet be used in the needed quantity and intensity.<ref name="ZG" /> One possibility for making the theorized long-lived nuclei of copernicium (<sup>291</sup>Cn and <sup>293</sup>Cn) and flerovium near the middle of the island, is using even heavier targets such as <sup>250</sup>[[curium|Cm]], <sup>249</sup>[[berkelium|Bk]], <sup>251</sup>[[californium|Cf]], and <sup>254</sup>[[einsteinium|Es]], that when fused with <sup>48</sup>Ca would yield isotopes such as <sup>291</sup>Mc and <sup>291</sup>Fl (as decay products of <sup>299</sup>Uue, <sup>295</sup>Ts, and <sup>295</sup>Lv), which may have just enough neutrons to alpha decay to nuclides close enough to the centre of the island to possibly undergo electron capture and move inward to the centre. However, reaction cross sections would be small and little is yet known about the decay properties of superheavies near the beta-stability line. This may be the current best hope to synthesize nuclei in the island of stability, but it is speculative and may or may not work in practice.<ref name="Zagrebaev" /> Another possibility is to use controlled [[nuclear explosion]]s to get the high [[neutron flux]] needed to make macroscopic amounts of such isotopes.<ref name="Zagrebaev" /> This would mimic the [[r-process]] where the actinides were first produced in nature and the gap of instability after [[polonium]] bypassed, as it would bypass the gaps of instability at <sup>258–260</sup>[[fermium|Fm]] and at [[mass number]] 275 (atomic numbers [[rutherfordium|104]] to 108).<ref name="Zagrebaev" /> Some such isotopes (especially <sup>291</sup>Cn and <sup>293</sup>Cn) may even have been synthesized in nature, but would decay far too quickly (with half-lives of only thousands of years) and be produced in far too small quantities (~10<sup>−12</sup> the abundance of lead) to be detectable today outside [[cosmic ray]]s.<ref name="Zagrebaev" />

===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 |bibcode=2021ACIE...60.7703M }}</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}}</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}}

===Chemical===
Flerovium is the heaviest known member of group 14, below lead, and is projected to be the second member of the 7p series of elements. Nihonium and flerovium are expected to form a very short subperiod corresponding to the filling of the 7p<sub>1/2</sub> orbital, coming between the filling of the 6d<sub>5/2</sub> and 7p<sub>3/2</sub> subshells. Their chemical behaviour is expected to be very distinctive: nihonium's homology to thallium has been called "doubtful" by computational chemists, while flerovium's to lead has been called only "formal".<ref name="Zaitsevskii">{{cite web|url=http://tan11.jinr.ru/pdf/07_Sep/S_3/04_Titov.pdf|title=Relativistic DFT and ab initio calculations on the seventh-row superheavy elements: E113 - E114|last1=Zaitsevskii|first1=A.|first2=C.|last2=van Wüllen|first3=A.|last3=Rusakov|first4=A.|last4=Titov|date=September 2007|website=jinr.ru|access-date=17 February 2018|archive-date=7 March 2021|archive-url=https://web.archive.org/web/20210307224719/http://tan11.jinr.ru/pdf/07_Sep/S_3/04_Titov.pdf|url-status=dead}}</ref>

The first five group 14 members show a +4 oxidation state and the latter members have increasingly prominent +2 chemistry due to onset of the inert pair effect. For tin, the +2 and +4 states are similar in stability, and lead(II) is the most stable of all the chemically well-understood +2 oxidation states in group 14.<ref name="Haire" /> The 7s orbitals are very highly stabilized in flerovium, so a very large sp<sup>3</sup> [[orbital hybridization]] is needed to achieve a +4 oxidation state, so flerovium is expected to be even more stable than lead in its strongly predominant +2 oxidation state and its +4 oxidation state should be highly unstable.<ref name="Haire" /> For example, the dioxide (FlO<sub>2</sub>) is expected to be highly unstable to decomposition into its constituent elements (and would not be formed by direct reaction of flerovium with oxygen),<ref name="Haire" />{{sfn|Pershina|2010|p=502}} and flerovane (FlH<sub>4</sub>), which should have Fl–H bond lengths of 1.787&nbsp;[[angstrom|Å]]<ref name="Schwerdtfeger" /> and would be the heaviest homologue of [[methane]] (the lighter compounds include [[silane]], [[germane]] and [[stannane]]), is predicted to be more thermodynamically unstable than [[plumbane]], spontaneously decomposing to flerovium(II) hydride (FlH<sub>2</sub>) and H<sub>2</sub>.{{sfn|Pershina|2010|p=503}} The tetrafluoride FlF<sub>4</sub>{{sfn|Thayer|2010|p=83}} would have bonding mostly due to ''sd'' hybridizations rather than ''sp''<sup>3</sup> hybridizations,<ref name="Fricke1971">{{cite journal|last1=Fricke|first1=B.|last2=Greiner|first2=W.|last3=Waber|first3=J. T.|date=1971|title=The continuation of the periodic table up to Z = 172. The chemistry of superheavy elements|journal=Theoretica Chimica Acta|volume=21|issue=3|pages=235–260|doi=10.1007/BF01172015|s2cid=117157377|url=https://kobra.bibliothek.uni-kassel.de/bitstream/urn:nbn:de:hebis:34-2008081923380/1/Fricke_continuation_1971.pdf|archive-date=4 March 2016|access-date=20 April 2018|archive-url=https://web.archive.org/web/20160304200000/https://kobra.bibliothek.uni-kassel.de/bitstream/urn:nbn:de:hebis:34-2008081923380/1/Fricke_continuation_1971.pdf}}</ref> and its decomposition to the difluoride and fluorine gas would be exothermic.<ref name="Schwerdtfeger" /> The other tetrahalides (for example, FlCl<sub>4</sub> is destabilized by about 400&nbsp;kJ/mol) decompose similarly.<ref name="Schwerdtfeger" /> The corresponding polyfluoride anion {{chem|FlF|6|2-}} should be unstable to [[hydrolysis]] in aqueous solution, and flerovium(II) polyhalide anions such as {{chem|FlBr|3|-}} and {{chem|FlI|3|-}} are predicted to form preferentially in solutions.<ref name="Haire" /> The ''sd'' hybridizations were suggested in early calculations, as flerovium's 7s and 6d electrons share about the same energy, which would allow a volatile [[hexafluoride]] to form, but later calculations do not confirm this possibility.<ref name="Fricke1971" /> In general, spin–orbit contraction of the 7p<sub>1/2</sub> orbital should lead to smaller bond lengths and larger bond angles: this has been theoretically confirmed in FlH<sub>2</sub>.<ref name="Schwerdtfeger" /> Still, even FlH<sub>2</sub> should be relativistically destabilized by 2.6&nbsp;eV to below Fl+H<sub>2</sub>; the large spin–orbit effects also break down the usual singlet–triplet divide in the group 14 dihydrides. FlF<sub>2</sub> and FlCl<sub>2</sub> are predicted to be more stable than FlH<sub>2</sub>.<ref>{{cite journal|last1=Balasubramanian|first1=K.|date=30 July 2002|title=Breakdown of the singlet and triplet nature of electronic states of the superheavy element 114 dihydride (114H<sub>2</sub>)|journal=Journal of Chemical Physics|volume=117|issue=16|pages=7426–32|doi=10.1063/1.1508371|bibcode=2002JChPh.117.7426B}}</ref>

Due to relativistic stabilization of flerovium's 7s<sup>2</sup>7p{{su|b=1/2|p=2|w=70%}} valence electron configuration, the 0 oxidation state should also be more stable for flerovium than for lead, as the 7p<sub>1/2</sub> electrons begin to also have a mild inert pair effect:<ref name="Haire" /> this stabilization of the neutral state may bring about some similarities between the behavior of flerovium and the noble gas [[radon]].<ref name="tanm" /> Due to flerovium's expected relative inertness, diatomic compounds FlH and FlF should have lower energies of [[dissociation (chemistry)|dissociation]] than the corresponding [[lead]] compounds PbH and PbF.<ref name="Schwerdtfeger" /> Flerovium(IV) should be even more electronegative than lead(IV);{{sfn|Thayer|2010|p=83}} lead(IV) has electronegativity 2.33 on the Pauling scale, though the lead(II) value is only 1.87. Flerovium could be a [[noble metal]].<ref name="Haire" />

Flerovium(II) should be more stable than lead(II), and halides FlX<sup>+</sup>, FlX<sub>2</sub>, {{chem|FlX|3|-}}, and {{chem|FlX|4|2-}} (X = [[chlorine|Cl]], [[bromine|Br]], [[iodine|I]]) are expected to form readily. The fluorides would undergo strong hydrolysis in aqueous solution.<ref name="Haire" /> All flerovium dihalides are expected to be stable;<ref name="Haire" /> the difluoride being water-soluble.<ref name="webelements">{{cite web|last=Winter|first=M.|date=2012|title=Flerovium: The Essentials|url=http://webelements.com/flerovium/|website=WebElements|publisher=[[University of Sheffield]]|access-date=28 August 2008}}</ref> Spin–orbit effects would destabilize the dihydride (FlH<sub>2</sub>) by almost {{convert|2.6|eVpar|kJ/mol|abbr=on}}.{{sfn|Pershina|2010|p=502}} In aqueous solution, the [[oxyanion]] flerovite ({{chem|FlO|2|2-}}) would also form, analogous to [[plumbite]]. Flerovium(II) sulfate (FlSO<sub>4</sub>) and sulfide (FlS) should be very insoluble in water, and flerovium(II) [[acetate]] (Fl(C<sub>2</sub>H<sub>3</sub>O<sub>2</sub>)<sub>2</sub>) and nitrate (Fl(NO<sub>3</sub>)<sub>2</sub>) should be quite water-soluble.<ref name="Fricke1971" /> The [[standard electrode potential]] for [[redox|reduction]] of Fl<sup>2+</sup> ion to metallic flerovium is estimated to be around +0.9&nbsp;V, confirming the increased stability of flerovium in the neutral state.<ref name="Haire" /> In general, due to relativistic stabilization of the 7p<sub>1/2</sub> spinor, Fl<sup>2+</sup> is expected to have properties intermediate between those of [[mercury (element)|Hg]]<sup>2+</sup> or [[cadmium|Cd]]<sup>2+</sup> and its lighter congener Pb<sup>2+</sup>.<ref name="Haire" />

==Experimental chemistry==
Flerovium's chemistry has been experimentally investigated, though studies so far are not conclusive. Flerovium's volatility has been measured through interactions with a gold surface, indicating that the volatility of flerovium was comparable to that of mercury, [[astatine]]. This volatile behavior was not expected for a usual group 14 metal.<ref name="2009ex">{{cite journal|last1=Eichler|first1=Robert|last2=Aksenov|first2=N. V.|last3=Albin|first3=Yu. V.|last4=Belozerov|first4=A. V.|last5=Bozhikov|first5=G. A.|last6=Chepigin|first6=V. I.|last7=Dmitriev|first7=S. N.|last8=Dressler|first8=R.|last9=Gäggeler|first9=H. W.|last10=Gorshkov|first10=V. A.|last11=Henderson|first11=G. S.|date=2010|title=Indication for a volatile element 114|journal=Radiochimica Acta|volume=98|issue=3|pages=133–139|doi=10.1524/ract.2010.1705|s2cid=95172228|url=http://doc.rero.ch/record/290779/files/ract.2010.1705.pdf}}</ref>

In experiments in 2012 at GSI, flerovium's chemistry was found to be more metallic than noble-gas-like. Jens Volker Kratz and Christoph Düllmann specifically named copernicium and flerovium as being in a new category of "volatile metals"; Kratz even speculated that they might be gases at [[standard temperature and pressure]].<ref name="Kratz">{{cite journal|last1=Kratz|first1=Jens Volker|date=2012|title=The impact of the properties of the heaviest elements on the chemical and physical sciences|journal=Radiochimica Acta|volume=100|issue=8–9|pages=569–578|doi=10.1524/ract.2012.1963|s2cid=97915854|doi-access=free}}</ref> These "volatile metals", as a category, were expected to fall between normal metals and noble gases in terms of adsorption properties.<ref name="Kratz" /> Interactions of flerovium and copernicium with gold were about equal.<ref name="Duellmann2012">{{cite conference|url=http://indico.cern.ch/contributionDisplay.py/pdf?contribId=71&sessionId=20&confId=183405|title=Superheavy element 114 is a volatile metal|last1=Düllmann|first1=Christoph E.|date=18 September 2012|access-date=25 September 2013|archive-url=https://web.archive.org/web/20130927093802/http://indico.cern.ch/contributionDisplay.py/pdf?contribId=71&sessionId=20&confId=183405|archive-date=27 September 2013}}</ref> Further studies showed that flerovium was more reactive than copernicium, in contradiction to previous experiments and predictions.<ref name="Kratz" />

In a 2014 paper detailing the experimental results of the chemical characterization of flerovium, the GSI group wrote: "[flerovium] is the least reactive element in the group, but still a metal."<ref>{{cite journal|last1=Yakushev|first1=Alexander|last2=Gates|first2=Jacklyn M.|first3=Andreas|last3=Türler|first4=Matthias|last4=Schädel|first5=Christoph E.|last5=Düllmann|first6=Dieter|last6=Ackermann|first7=Lise-Lotte|last7=Andersson|first8=Michael|last8=Block|first9=Willy|last9=Brüchle|first10=Jan|last10=Dvorak|first11=Klaus|last11=Eberhardt|first12=Hans G.|last12=Essel|first13=Julia|last13=Even|first14=Ulrika|last14=Forsberg|first15=Alexander|last15=Gorshkov|first16=Reimar|last16=Graeger|first17=Kenneth E.|last17=Gregorich|first18=Willi|last18=Hartmann|first19=Rolf-Deitmar|last19=Herzberg|first20=Fritz P.|last20=Heßberger|first21=Daniel|last21=Hild|first22=Annett|last22=Hübner|first23=Egon|last23=Jäger|first24=Jadambaa|last24=Khuyagbaatar|first25=Birgit|last25=Kindler|first26=Jens V.|last26=Kratz|first27=Jörg|last27=Krier|first28=Nikolaus|last28=Kurz|first29=Bettina|last29=Lommel|first30=Lorenz J.|last30=Niewisch|first31=Heino|last31=Nitsche|first32=Jon Petter|last32=Omtvedt|first33=Edward|last33=Parr|first34=Zhi|last34=Qin|first35=Dirk|last35=Rudolph|first36=Jörg|last36=Runke|first37=Birgitta|last37=Schausten|first38=Erwin|last38=Schimpf|first39=Andrey|last39=Semchenkov|first40=Jutta|last40=Steiner|first41=Petra|last41=Thörle-Pospiech|first42=Juha|last42=Uusitalo|first43=Maciej|last43=Wegrzecki|first44=Norbert|last44=Wiehl|date=2014|title=Superheavy Element Flerovium (Element 114) Is a Volatile Metal|url=http://portal.research.lu.se/portal/files/1614031/4362246.pdf|journal=Inorg. Chem.|volume=53|issue=1624|doi=10.1021/ic4026766|pmid=24456007|access-date=30 March 2017|pages=1624–1629|s2cid=5140723}}</ref> Nevertheless, in a 2016 conference about chemistry and physics of heavy and superheavy elements, Alexander Yakushev and Robert Eichler, two scientists who had been active at GSI and FLNR in determining flerovium's chemistry, still urged caution based on the inconsistencies of the various experiments previously listed, noting that the question of whether flerovium was a metal or a noble gas was still open with the known evidence: one study suggested a weak noble-gas-like interaction between flerovium and gold, while the other suggested a stronger metallic interaction.<ref>{{cite conference|url=http://www.epj-conferences.org/articles/epjconf/pdf/2016/26/epjconf-NS160-07003.pdf|title=Gas-phase chemistry of element 114, flerovium|last1=Yakushev|first1=Alexander|last2=Eichler|first2=Robert|date=2016|conference=Nobel Symposium NS160 – Chemistry and Physics of Heavy and Superheavy Elements|doi=10.1051/epjconf/201613107003|doi-access=free}}</ref> The longer-lived isotope {{chem2|^{289}Fl}} has been considered of interest for future radiochemical studies.<ref name="Moody">{{cite book|chapter=Synthesis of Superheavy Elements|last1=Moody|first1=Ken|editor1-first=Matthias|editor1-last=Schädel|editor2-first=Dawn|editor2-last=Shaughnessy|title=The Chemistry of Superheavy Elements|publisher=Springer Science & Business Media|edition=2nd|pages=24–8|isbn=978-3-642-37466-1|date=2013-11-30}}</ref>

Experiments published in 2022 suggest that flerovium is a metal, exhibiting lower reactivity towards gold than mercury, but higher reactivity than radon. The experiments could not identify if the adsorption was due to elemental flerovium (considered more likely), or if it was due to a flerovium compound such as FlO that was more reactive towards gold than elemental flerovium, but both scenarios involve flerovium forming chemical bonds.<ref>{{cite news|last=Ingo|first=Peter|date=15 September 2022|title=Study shows flerovium is the most volatile metal in the periodic table|url=https://phys.org/news/2022-09-flerovium-volatile-metal-periodic-table.html|work=phys.org<!--but provided by GSI Helmholtz-->|location=|access-date=22 November 2022}}</ref><ref>{{cite journal|last1=Yakushev|first1=A.|last2=Lens|first2=L.|first3=Ch. E.|last3=Düllmann|first4=J.|last4=Khuyagbaatar|first5=E.|last5=Jäger|first6=J.|last6=Krier|first7=J.|last7=Runke|first8=H. M.|last8=Albers|first9=M.|last9=Asai|first10=M.|last10=Block|first11=J.|last11=Despotopulos|first12=A.|last12=Di Nitto|first13=K.|last13=Eberhardt|first14=U.|last14=Forsberg|first15=P.|last15=Golubev|first16=M.|last16=Götz|first17=S.|last17=Götz|first18=H.|last18=Haba|first19=L.|last19=Harkness-Brennan|first20=R.-D.|last20=Herzberg|first21=F. P.|last21=Heßberger|first22=D.|last22=Hinde|first23=A.|last23=Hübner|first24=D.|last24=Judson|first25=B.|last25=Kindler|first26=Y.|last26=Komori|first27=J.|last27=Konki|first28=J. V.|last28=Kratz|first29=N.|last29=Kurz|first30=M.|last30=Laatiaoui|first31=S.|last31=Lahiri|first32=B.|last32=Lommel|first33=M.|last33=Maiti|first34=A. K.|last34=Mistry|first35=Ch.|last35=Mokry|first36=K. J.|last36=Moody|first37=Y.|last37=Nagame|first38=J. P.|last38=Omtvedt|first39=P.|last39=Papadakis|first40=V.|last40=Pershina|first41=D.|last41=Rudolph|first42=L. G.|last42=Samiento|first43=T. K.|last43=Sato|first44=M.|last44=Schädel|first45=P.|last45=Scharrer|first46=B.|last46=Schausten|first47=D. A.|last47=Shaughnessy|first48=J.|last48=Steiner|first49=P.|last49=Thörle-Pospiech|first50=A.|last50=Toyoshima|first51=N.|last51=Trautmann|first52=K.|last52=Tsukada|first53=J.|last53=Uusitalo|first54=K.-O.|last54=Voss|first55=A.|last55=Ward|first56=M.|last56=Wegrzecki|first57=N.|last57=Wiehl|first58=E.|last58=Williams|first59=V.|last59=Yakusheva|display-authors=3|date=25 August 2022|title=On the adsorption and reactivity of element 114, flerovium|journal=Frontiers in Chemistry|volume=10|article-number=976635|doi=10.3389/fchem.2022.976635|pmid=36092655|pmc=9453156|bibcode=2022FrCh...10.6635Y|doi-access=free}}</ref>

==See also==
* [[Island of stability]]: '''Flerovium'''–[[Unbinilium]]–[[Unbihexium]]
* [[Isotopes of flerovium]]
* [[Extended periodic table]]
{{Subject bar
|portal=Chemistry
|book1=Flerovium
|book2=Period 7 elements
|book3=Carbon group
|book4=Chemical elements (sorted&nbsp;alphabetically)
|book5=Chemical elements (sorted by number)
|commons=y
|wikt=y
|wikt-search=flerovium
}}

==Notes==
{{notelist}}

==References==
{{Reflist|30em|refs=

<ref name=Haire>{{cite book| title=The Chemistry of the Actinide and Transactinide Elements| editor1-last=Morss| editor2-first=Norman M.| editor2-last=Edelstein| editor3-last=Fuger| editor3-first=Jean| last1=Hoffman| first1=Darleane C.| last2=Lee| first2=Diana M.| last3=Pershina| first3=Valeria| chapter=Transactinides and the future elements| publisher=[[Springer Science+Business Media]]| year=2006| isbn=978-1-4020-3555-5| location=Dordrecht, The Netherlands| edition=3rd| ref=CITEREFHaire2006}}</ref>

<ref name=Schwerdtfeger>{{cite journal |last1=Schwerdtfeger |first1=Peter |last2=Seth |first2=Michael |date=2002 |title=Relativistic Quantum Chemistry of the Superheavy Elements. Closed-Shell Element 114 as a Case Study |url=http://www.radiochem.org/paper/JN31/30.pdf |journal=Journal of Nuclear and Radiochemical Sciences |volume=3 |issue=1 |pages=133–136 |access-date=12 September 2014|doi=10.14494/jnrs2000.3.133 }}</ref>

}}

== Bibliography ==

* {{cite journal|title=The NUBASE2016 evaluation of nuclear properties|doi=10.1088/1674-1137/41/3/030001|last1=Audi|first1=G.|last2=Kondev|first2=F. G.|last3=Wang|first3=M.|last4=Huang|first4=W. J.|last5=Naimi|first5=S.|display-authors=3|journal=Chinese Physics C|volume=41|issue=3 <!--Citation bot deny-->|year=2017 |at=030001|bibcode=2017ChPhC..41c0001A|ref={{sfnref|Audi et al.|2017}}}}
<!--for consistency and specific pages, do not replace with {{NUBASE2016}}-->
** [http://cms.iopscience.org/ac0c0614-0d60-11e7-9a47-19ee90157113/030001.pdf?guest=true pp. 030001-1–030001-17]
** [http://cms.iopscience.org/b3dbafd9-0d60-11e7-9a47-19ee90157113/030001_Table1.pdf?guest=true pp. 030001-18–030001-138, Table I. The NUBASE2016 table of nuclear and decay properties]
* {{cite book|last=Beiser|first=A.|title=Concepts of modern physics|date=2003|publisher=McGraw-Hill|isbn=978-0-07-244848-1|edition=6th|oclc=48965418}}
* {{cite book|last1=Hoffman|first1=D. C.|author-link=Darleane C. Hoffman|last2=Ghiorso|first2=A.|author-link2=Albert Ghiorso|last3=Seaborg|first3=G. T.|title=The Transuranium People: The Inside Story|year=2000|publisher=[[World Scientific]]|isbn=978-1-78-326244-1|ref=CITEREFHoffman2000}}
* {{cite book|last=Kragh|first=H.|author-link=Helge Kragh|date=2018|title=From Transuranic to Superheavy Elements: A Story of Dispute and Creation|publisher=[[Springer Science+Business Media|Springer]]|isbn=978-3-319-75813-8}}
* {{cite journal|last1=Zagrebaev|first1=V.|last2=Karpov|first2=A.|last3=Greiner|first3=W.|date=2013|title=Future of superheavy element research: Which nuclei could be synthesized within the next few years?|journal=[[Journal of Physics: Conference Series]]|volume=420|issue=1|article-number=012001|doi=10.1088/1742-6596/420/1/012001|arxiv=1207.5700|bibcode=2013JPhCS.420a2001Z|s2cid=55434734|issn=1742-6588|ref=CITEREFZagrebaev2013}}

{{refbegin}}
* {{cite book
|editor1-last=Barysz|editor1-first=M.
|editor2-last=Ishikawa|editor2-first=Y.
|date=2010
|title=Relativisic Methods for Chemists
|url=https://books.google.com/books?id=QbDEC3oL7uAC
|publisher=[[Springer (publisher)|Springer]]
|isbn=978-1-4020-9974-8
}}<!--the citation style for the below three is correct. Those are chapters of the book in this line.-->
:*{{cite book
|last=Thayer|first=J. S.
|date=2010
|doi=10.1007/978-1-4020-9975-5_2
|title=Relativistic Methods for Chemists
|volume=10
|pages=63–97
|isbn=978-1-4020-9974-8
|chapter=Relativistic Effects and the Chemistry of the Heavier Main Group Elements
|series=Challenges and Advances in Computational Chemistry and Physics
}}
:*{{cite book
|last=Stysziński|first=J.
|date=2010
|title=Why do we need relativistic computational methods?
|page=99
}}
:*{{cite book
|last=Pershina|first=V.
|date=2010
|title=Electronic structure and chemistry of the heaviest elements
|page=450
}}
{{refend}}

==External links==
{{Commons category}}
* [https://web.archive.org/web/20080723144358/http://www.cerncourier.com/main/article/39/7/18 ''CERN Courier'' – First postcard from the island of nuclear stability]
* [https://web.archive.org/web/20081205080201/http://www.cerncourier.com/main/article/41/8/17 ''CERN Courier'' – Second postcard from the island of stability]

{{Periodic table (navbox)}}
{{authority control}}

[[Category:Flerovium| ]]
[[Category:Chemical elements]]
[[Category:Synthetic elements]]