Editing Flerovium (section)

==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">{{cite conference|last1=Kratz|first1=J. V.|date=5 September 2011|title=The Impact of Superheavy Elements on the Chemical and Physical Sciences|url=http://tan11.jinr.ru/pdf/06_Sep/S_1/02_Kratz.pdf|conference=4th International Conference on the Chemistry and Physics of the Transactinide Elements|access-date=27 August 2013}}</ref><!--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 |url-status=dead |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]] |df=dmy-all}}</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|url-status=dead}}</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|page=064609|bibcode=2004PhRvC..70f4609O|doi=10.1103/PhysRevC.70.064609|url-status=dead|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=9789813226555}}</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|page=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|page=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|pages=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|url-status=dead|df=dmy-all}}</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|url-status=dead}}</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}}