Editing Island of stability (section)

==Discoveries==
{|class="wikitable sortable" style="float:left; margin-right:1em; font-size:85%;"
|+Most stable isotopes of superheavy elements (''Z''&nbsp;≥&nbsp;104)
|-
!rowspan=2|Element
!rowspan=2|Atomic<br />number
!rowspan=2|Most<br />stable<br />isotope
!colspan=2|Half-life{{efn|Different sources give different values for half-lives; the most recently published values in the literature and NUBASE are both listed for reference.}}
|-
!Publications<br /><ref>{{harvnb|Emsley|2011|p=566}}</ref><ref name=shesummary>{{cite journal |last1=Oganessian |first1=Yu. Ts. |last2=Utyonkov |first2=V. K. |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=036301-14–036301-15 <!-- Deny Citation Bot-->|doi=10.1088/0034-4885/78/3/036301 |pmid=25746203 |bibcode=2015RPPh...78c6301O|s2cid=37779526 }}</ref>
!NUBASE 2020<br />{{NUBASE2020 |ref |page=030001-174–030001-180}}
|-
|[[Rutherfordium]]||104||[[isotopes of rutherfordium|<sup>267</sup>Rf]]||data-sort-value=2880|48 min<ref name=PuCa2022>{{cite journal |title=Investigation of <sup>48</sup>Ca-induced reactions with <sup>242</sup>Pu and <sup>238</sup>U targets at the JINR Superheavy Element Factory |journal=Physical Review C |volume=106 |number=24612 |year=2022 |first1=Yu. Ts. |last1=Oganessian |first2=V. K. |last2=Utyonkov |first3=D. |last3=Ibadullayev |page=024612 |display-authors=et al. |doi= 10.1103/PhysRevC.106.024612|bibcode=2022PhRvC.106b4612O |osti=1883808 |s2cid=251759318 }}</ref>||data-sort-value=9000|2.5 h
|-
|[[Dubnium]]||105||[[isotopes of dubnium|<sup>268</sup>Db]]||data-sort-value=57600|16 h<ref name=SHEfactory0922>{{cite journal |last1=Oganessian |first1=Yu. Ts. |last2=Utyonkov |first2=V. K. |last3=Kovrizhnykh |first3=N. D. |last4=Abdullin |first4=F. Sh. |last5=Dmitriev |first5=S. N. |last6=Ibadullayev |first6=D. |last7=Itkis |first7=M. G. |last8=Kuznetsov |first8=D. A. |last9=Petrushkin |first9=O. V. |last10=Podshibiakin |first10=A. V. |last11=Polyakov |first11=A. N. |last12=Popeko |first12=A. G. |last13=Sagaidak |first13=R. N. |last14=Schlattauer |first14=L. |last15=Shirokovski |first15=I. V. |last16=Shubin |first16=V. D. |last17=Shumeiko |first17=M. V. |last18=Solovyev |first18=D. I. |last19=Tsyganov |first19=Yu. S. |last20=Voinov |first20=A. A. |last21=Subbotin |first21=V. G. |last22=Bodrov |first22=A. Yu. |last23=Sabel'nikov |first23=A. V. |last24=Khalkin |first24=A. V. |last25=Zlokazov |first25=V. B. |last26=Rykaczewski |first26=K. P. |last27=King |first27=T. T. |last28=Roberto |first28=J. B. |last29=Brewer |first29=N. T. |last30=Grzywacz |first30=R. K. |last31=Gan |first31=Z. G. |last32=Zhang |first32=Z. Y. |last33=Huang |first33=M. H. |last34=Yang |first34=H. B. |display-authors=3 |title=First experiment at the Super Heavy Element Factory: High cross section of <sup>288</sup>Mc in the<sup>243</sup>Am+<sup>48</sup>Ca reaction and identification of the new isotope <sup>264</sup>Lr |journal=Physical Review C |date=29 September 2022 |volume=106 |issue=3 |pages=L031301 |doi=10.1103/PhysRevC.106.L031301 |bibcode=2022PhRvC.106c1301O |osti=1890311 |s2cid=252628992 |url=https://journals.aps.org/prc/abstract/10.1103/PhysRevC.106.L031301}}</ref>||data-sort-value=104400|1.2 d
|-
|[[Seaborgium]]||106||[[isotopes of seaborgium|<sup>269</sup>Sg]]||data-sort-value=840|14 min<ref name=PuCa2017 />||data-sort-value=300|5 min
|-
|[[Bohrium]]||107||[[isotopes of bohrium|<sup>270</sup>Bh]]{{efn|The unconfirmed <sup>278</sup>Bh may have a longer half-life of 11.5 minutes.<ref name=Hofmann2016 />}}||data-sort-value=144|2.4 min<ref name=Mc2022>{{Cite journal |title=New isotope <sup>286</sup>Mc produced in the <sup>243</sup>Am+<sup>48</sup>Ca reaction |last1=Oganessian |first1=Yu. Ts. |last2=Utyonkov |first2=V. K. |last3=Kovrizhnykh |first3=N. D. |display-authors=et al. |date=2022 |journal=Physical Review C |volume=106 |number=64306 |page=064306 |doi=10.1103/PhysRevC.106.064306|bibcode=2022PhRvC.106f4306O |s2cid=254435744 |doi-access=free }}</ref>||data-sort-value=228|3.8 min
|-
|[[Hassium]]||108||[[isotopes of hassium|<sup>269</sup>Hs]]||data-sort-value=9.7|9.7 s<ref name=chemHs>{{cite journal |last=Schädel |first=M. |date=2015 |title=Chemistry of the superheavy elements |journal=Philosophical Transactions of the Royal Society A |volume=373 |issue=2037 |pages=20140191–9 |doi=10.1098/rsta.2014.0191 |pmid=25666065 |bibcode=2015RSPTA.37340191S |s2cid=6930206 |doi-access=free }}</ref>||data-sort-value=16|16 s
|-
|[[Meitnerium]]||109||[[isotopes of meitnerium|<sup>278</sup>Mt]]{{efn|name=X|For elements&nbsp;109–118, the longest-lived known isotope is always the heaviest discovered thus far. This makes it seem likely that there are longer-lived undiscovered isotopes among the even heavier ones.<ref name=48Ca />}}{{efn|The unconfirmed <sup>282</sup>Mt may have a longer half-life of 1.1 minutes.<ref name=Hofmann2016 />}}||data-sort-value=4.5|4.5 s||data-sort-value=6|6 s
|-
|[[Darmstadtium]]||110||[[isotopes of darmstadtium|<sup>281</sup>Ds]]{{efn|name=X}}||data-sort-value=12.7|12.7 s||data-sort-value=14|14 s
|-
|[[Roentgenium]]||111||[[isotopes of roentgenium|<sup>282</sup>Rg]]{{efn|name=X}}{{efn|The unconfirmed <sup>286</sup>Rg may have a longer half-life of 10.7 minutes.<ref name=Hofmann2016 />}}||data-sort-value=100|1.7 min||data-sort-value=130|2.2 min
|-
|[[Copernicium]]||112||[[isotopes of copernicium|<sup>285</sup>Cn]]{{efn|name=X}}||data-sort-value=28|28 s||data-sort-value=30|30 s
|-
|[[Nihonium]]||113||[[isotopes of nihonium|<sup>286</sup>Nh]]{{efn|name=X}}||data-sort-value=9.5|9.5 s||data-sort-value=12|12 s
|-
|[[Flerovium]]||114||[[isotopes of flerovium|<sup>289</sup>Fl]]{{efn|name=X}}{{efn|The unconfirmed <sup>290</sup>Fl may have a longer half-life of 19 seconds.<ref name=Hofmann2016 />}}||data-sort-value=1.9|1.9 s||data-sort-value=2.1|2.1 s
|-
|[[Moscovium]]||115||[[isotopes of moscovium|<sup>290</sup>Mc]]{{efn|name=X}}||data-sort-value=0.65|650 ms||data-sort-value=0.84|840 ms
|-
|[[Livermorium]]||116||[[isotopes of livermorium|<sup>293</sup>Lv]]{{efn|name=X}}||data-sort-value=0.057|57 ms||data-sort-value=0.07|70 ms
|-
|[[Tennessine]]||117||[[isotopes of tennessine|<sup>294</sup>Ts]]{{efn|name=X}}||data-sort-value=0.051|51 ms||data-sort-value=0.07|70 ms
|-
|[[Oganesson]]||118||[[isotopes of oganesson|<sup>294</sup>Og]]{{efn|name=X}}||data-sort-value=0.00069|690 μs||data-sort-value=0.0007|700 μs
|}

Interest in a possible island of stability grew throughout the 1960s, as some calculations suggested that it might contain nuclides with half-lives of billions of years.<ref name=lodhi11>{{harvnb|Lodhi|1978|p=11}}</ref><ref name=nuclei>{{cite journal |last=Oganessian |first=Yu. Ts. |year=2012 |title=Nuclei in the "Island of Stability" of Superheavy Elements |journal=[[Journal of Physics: Conference Series]] |volume=337 |issue=1 |page=012005 |bibcode=2012JPhCS.337a2005O |doi=10.1088/1742-6596/337/1/012005|doi-access=free }}</ref> They were also predicted to be especially stable against spontaneous fission in spite of their high atomic mass.<ref name=quest /><ref name="Cwiok">{{cite journal |last1=Ćwiok |first1=S. |last2=Heenen |first2=P.-H. |last3=Nazarewicz |first3=W. |year=2005 |title=Shape coexistence and triaxiality in the superheavy nuclei |url=http://www.phys.utk.edu/witek/fission/utk/Papers/natureSHE.pdf |journal=[[Nature (journal)|Nature]] |volume=433 |issue=7027 |pages=705–709 |bibcode=2005Natur.433..705C |doi=10.1038/nature03336 |pmid=15716943 |s2cid=4368001 |url-status=dead |archive-url=https://web.archive.org/web/20100623081932/http://www.phys.utk.edu/witek/fission/utk/Papers/natureSHE.pdf |archive-date=23 June 2010 }}</ref> It was thought that if such elements exist and are sufficiently long-lived, there may be several novel applications as a consequence of their nuclear and chemical properties. These include use in [[particle accelerator]]s as [[neutron source]]s, in [[nuclear weapon]]s as a consequence of their predicted low [[critical mass]]es and high number of neutrons emitted per fission,<ref>{{cite book |last1=Gsponer |first1=A. |last2=Hurni |first2=J.-P. |year=2009 |title=Fourth Generation Nuclear Weapons: The physical principles of thermonuclear explosives, inertial confinement fusion, and the quest for fourth generation nuclear weapons |edition=3rd printing of the 7th |pages=110–115 |url=https://cryptome.org/2014/06/wmd-4th-gen-quest.pdf}}</ref> and as [[nuclear fuel]] to power space missions.<ref name=newsci10>{{cite news |last=Courtland |first=R. |title=Weight scale for atoms could map 'island of stability' |date=2010 |access-date=4 July 2019 |publisher=NewScientist |url=https://www.newscientist.com/article/dn18510-weight-scale-for-atoms-could-map-island-of-stability/}}</ref> These speculations led many researchers to conduct searches for superheavy elements in the 1960s and 1970s, both in nature and through [[nucleosynthesis]] in particle accelerators.<ref name=ghiorso1 />

During the 1970s, many searches for long-lived superheavy nuclei were conducted. Experiments aimed at synthesizing elements ranging in atomic number from 110 to 127 were conducted at laboratories around the world.<ref name=LodhiTable>{{harvnb|Lodhi|1978|p=35}}</ref><ref name=emsley>{{harvnb|Emsley|2011|p=588}}</ref> These elements were sought in fusion-evaporation reactions, in which a heavy target made of one nuclide is [[irradiation#Ion irradiation|irradiated]] by accelerated ions of another in a [[cyclotron]], and new nuclides are produced after these nuclei [[nuclear fusion|fuse]] and the resulting excited system releases energy by evaporating several particles (usually protons, neutrons, or alpha particles). These reactions are divided into "cold" and "hot" fusion, which respectively create systems with lower and higher [[excited state|excitation]] energies; this affects the yield of the reaction.<ref name=JK17>{{cite journal  |last=Khuyagbaatar |first=J. |date=2017 |title=The cross sections of fusion-evaporation reactions: the most promising route to superheavy elements beyond ''Z''&nbsp;=&nbsp;118 |journal=EPJ Web of Conferences |volume=163 |pages=00030-1–00030-5 <!-- Deny Citation Bot-->|doi=10.1051/epjconf/201716300030 |bibcode=2017EPJWC.16300030J |url=https://www.researchgate.net/publication/321229825|doi-access=free }}</ref> For example, the reaction between <sup>248</sup>Cm and <sup>40</sup>Ar was expected to yield isotopes of element 114, and that between <sup>232</sup>Th and <sup>84</sup>Kr was expected to yield isotopes of element 126.<ref name=H404>{{harvnb|Hoffman|2000|p=404}}</ref> None of these attempts were successful,<ref name=LodhiTable/><ref name=emsley>{{harvnb|Emsley|2011|p=588}}</ref> indicating that such experiments may have been insufficiently sensitive if reaction [[cross section (physics)|cross sections]] were low—resulting in lower yields—or that any nuclei reachable via such fusion-evaporation reactions might be too short-lived for detection.{{efn|name=microsec}} Subsequent successful experiments reveal that half-lives and cross sections indeed decrease with increasing atomic number, resulting in the synthesis of only a few short-lived atoms of the heaviest elements in each experiment;<ref name="Karpov2015">{{cite web<!--Citation bot deny--> |url=https://cyclotron.tamu.edu/she2015/assets/pdfs/presentations/Karpov_SHE_2015_TAMU.pdf |title=Superheavy Nuclei: Which regions of nuclear map are accessible in the nearest studies? |last=Karpov |first=A. |last2=Zagrebaev |first2=V. |last3=Greiner |first3=W. |date=2015 |pages=1–16 |work=SHE-2015 |access-date=30 October 2018}}</ref> {{As of|2022|lc=y}}, the highest reported cross section for a superheavy nuclide near the island of stability is for <sup>288</sup>Mc in the reaction between <sup>243</sup>Am and <sup>48</sup>Ca.<ref name=SHEfactory0922/>

Similar searches in nature were also unsuccessful, suggesting that if superheavy elements do exist in nature, their abundance is less than 10<sup>−14</sup> [[mole (chemistry)|moles]] of superheavy elements per mole of ore.<ref>{{harvnb|Hoffman|2000|p=403}}</ref> Despite these unsuccessful attempts to observe long-lived superheavy nuclei,<ref name=quest /> new superheavy elements were synthesized [[timeline of chemical element discoveries|every few years]] in laboratories through [[Nuclear fusion#Beam–beam or beam–target fusion|light-ion bombardment]] and cold fusion{{efn|This is a distinct concept from hypothetical fusion near room temperature ([[cold fusion]]); it instead refers to fusion reactions with lower excitation energy.}} reactions; rutherfordium, the first [[transactinide]], was discovered in 1969, and copernicium, eight protons closer to the island of stability predicted at ''Z''&nbsp;=&nbsp;114, was reached by 1996. Even though the half-lives of these nuclei are very short (on the order of [[second]]s),{{NUBASE2020 |ref |page=030001-174–030001-180}} the very existence of elements heavier than rutherfordium is indicative of stabilizing effects thought to be caused by closed shells; a [[semi-empirical mass formula|model not considering such effects]] would forbid the existence of these elements due to rapid spontaneous fission.<ref name=liquiddrop>{{cite journal |last=Möller |first=P. |date=2016 |title=The limits of the nuclear chart set by fission and alpha decay |journal=EPJ Web of Conferences |volume=131 |pages=03002-1–03002-8<!-- Deny Citation Bot--> |url=http://inspirehep.net/record/1502715/files/epjconf-NS160-03002.pdf |doi=10.1051/epjconf/201613103002 |bibcode=2016EPJWC.13103002M|doi-access=free }}</ref>

Flerovium, with the expected magic 114 protons, was first synthesized in 1998 at the [[Joint Institute for Nuclear Research]] in [[Dubna]], Russia, by a group of physicists led by [[Yuri Oganessian]]. A single atom of element 114 was detected, with a lifetime of 30.4 seconds, and its [[decay product]]s had half-lives measurable in minutes.<ref name="99Og01">{{cite journal |last1=Oganessian |first1=Yu. Ts. |last2=Utyonkov |first2=V. K. |last3=Lobanov |first3=Yu. V. |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=31 December 2018 |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> Because the produced nuclei underwent alpha decay rather than fission, and the half-lives were several [[orders of magnitude (time)|orders of magnitude]] longer than those previously predicted{{efn|Oganessian stated that element 114 would have a half-life on the order of 10<sup>−19</sup>&nbsp;s in the absence of stabilizing effects in the vicinity of the theorized island.<ref name=whatittakes>{{cite web |last=Chapman |first=K. |date=2016 |title=What it takes to make a new element |url=https://www.chemistryworld.com/what-it-takes-to-make-a-new-element/1017677.article |publisher=[[Chemistry World]] |access-date=16 January 2020}}</ref>}} or observed for superheavy elements,<ref name="99Og01"/> this event was seen as a "textbook example" of a decay chain characteristic of the island of stability, providing strong evidence for the existence of the island of stability in this region.<ref>{{harvnb|Hoffman|2000|p=426}}</ref> Even though the original 1998 chain was not observed again, and its assignment remains uncertain,<ref name="Hofmann2016">{{cite journal |last1=Hofmann |first1=S. |last2=Heinz |first2=S. |last3=Mann |first3=R. |last4=Maurer |first4=J. |last5=Münzenberg |first5=G. |last6=Antalic |first6=S. |last7=Barth |first7=W. |last8=Burkhard |first8=H. G. |last9=Dahl |first9=L. |last10=Eberhardt |first10=K. |last11=Grzywacz |first11=R. |last12=Hamilton |first12=J. H. |last13=Henderson |first13=R. A. |last14=Kenneally |first14=J. M. |last15=Kindler |first15=B. |display-authors=3 |date=2016 |title=Review of even element super-heavy nuclei and search for element 120 |url=https://www.researchgate.net/publication/304459935 |journal=The European Physical Journal A |volume=2016 |issue=52 |pages=180-15–180-17<!-- Deny Citation Bot--> |bibcode=2016EPJA...52..180H |doi=10.1140/epja/i2016-16180-4 |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=Scheidenberger |first30=H. J. |last30=Schött |first31=D. A. |last31=Shaughnessy |first32=M. A. |last32=Stoyer |first33=P. |last33=Thörle-Popiesch |first34=K. |last34=Tinschert |first35=N. |last35=Trautmann |first36=J. |last36=Uusitalo |first37=A. V. |last37=Yeremin |s2cid=124362890}}</ref> further successful experiments in the next two decades led to the discovery of all elements up to [[oganesson]], whose half-lives were found to exceed initially predicted values; these decay properties further support the presence of the island of stability.<ref name=beachhead>{{cite journal |last1=Oganessian |first1=Yu. Ts. |last2=Rykaczewski |first2=K. |title=A beachhead on the island of stability |date=2015 |journal=Physics Today |volume=68 |issue=8 |pages=32–38 |doi=10.1063/PT.3.2880 |url=https://www.researchgate.net/publication/282806685 |bibcode=2015PhT....68h..32O|osti=1337838 |s2cid=119531411 |doi-access=free }}</ref><ref name=48Ca>{{cite journal |last=Oganessian |first=Yu. Ts. |title=Heaviest nuclei from <sup>48</sup>Ca-induced reactions |date=2007 |journal=Journal of Physics G: Nuclear and Particle Physics |volume=34 |issue=4 |pages=R233 |doi=10.1088/0954-3899/34/4/R01 |url=https://www.nucleonica.com/wiki/images/4/41/Oganessian.pdf |bibcode=2007JPhG...34R.165O}}</ref><ref name="117s">{{cite journal|last1=Oganessian |first1=Yu. Ts.|last2=Abdullin |first2=F. Sh.|last3=Bailey |first3=P. D. |last4=Benker |first4=D. E.|last5=Bennett |first5=M. E.|last6=Dmitriev |first6=S. N.|last7=Ezold |first7=J. G.|last8=Hamilton |first8=J. H.|last9=Henderson |first9=R. A. | first10=M. G. |last10=Itkis | first11=Yuri V. |last11=Lobanov | first12=A. N. |last12=Mezentsev | first13=K. J. |last13=Moody | first14=S. L. |last14=Nelson | first15=A. N. |last15=Polyakov | first16=C. E. |last16=Porter | first17=A. V. |last17=Ramayya | first18=F. D. |last18=Riley | first19=J. B.|last19=Roberto | first20=M. A. |last20=Ryabinin | first21=K. P. |last21=Rykaczewski | first22=R. N. |last22=Sagaidak | first23=D. A. |last23=Shaughnessy | first24=I. V. |last24=Shirokovsky | first25=M. A. |last25=Stoyer | first26=V. G. |last26=Subbotin | first27=R. |last27=Sudowe | first28=A. M. |last28=Sukhov | first29=Yu. S. |last29=Tsyganov | first30=Vladimir K. |last30=Utyonkov | first31=A. A. |last31=Voinov | first32=G. K. |last32=Vostokin | first33=P. A. |last33=Wilk|title=Synthesis of a New Element with Atomic Number ''Z'' = 117 |year=2010 |journal=Physical Review Letters |volume=104 |issue=14 |pages=142502-1–142502-4 <!-- Deny Citation Bot-->|doi=10.1103/PhysRevLett.104.142502 |pmid=20481935 |bibcode=2010PhRvL.104n2502O |url=https://www.researchgate.net/publication/44610795 |display-authors=3 |doi-access=free }}</ref> However, a 2021 study on the decay chains of flerovium isotopes suggests that there is no strong stabilizing effect from ''Z''&nbsp;=&nbsp;114 in the region of known nuclei (''N''&nbsp;=&nbsp;174),<ref name=280Ds2021>{{Cite journal |doi = 10.1103/PhysRevLett.126.032503 |issn=0031-9007|title = Spectroscopy along Flerovium Decay Chains: Discovery of <sup>280</sup>Ds and an Excited State in <sup>282</sup>Cn|journal = Physical Review Letters|volume = 126|pages = 032503-1–032503-7|year = 2021|last1 = Såmark-Roth|first1 = A.|last2 = Cox|first2 = D. M.|last3 = Rudolph|first3 = D.|last4 = Sarmento|first4 = L. G.|last5 = Carlsson|first5 = B. G.|last6 = Egido|first6 = J. L.|last7 = Golubev|first7 = P|last8 = Heery|first8 = J.|last9 = Yakushev|first9 = A.|last10 = Åberg|first10 = S.|last11 = Albers|first11 = H. M.|last12 = Albertsson|first12 = M.|last13 = Block|first13 = M.|last14 = Brand|first14 = H.|last15 = Calverley|first15 = T.|last16 = Cantemir|first16 = R.|last17 = Clark|first17 = R. M.|last18 = Düllmann|first18 = Ch. E.|last19 = Eberth|first19 = J.|last20 = Fahlander|first20 = C.|last21 = Forsberg|first21 = U.|last22 = Gates|first22 = J. M.|last23 = Giacoppo|first23 = F.|last24 = Götz|first24 = M.|last25 = Hertzberg|first25 = R.-D.|last26 = Hrabar|first26 = Y.|last27 = Jäger|first27 = E.|last28 = Judson|first28 = D.|last29 = Khuyagbaatar|first29 = J.|last30 = Kindler|first30 = B.|issue = 3|pmid = 33543956|bibcode = 2021PhRvL.126c2503S|display-authors = 3|doi-access = free|hdl = 10486/705608|hdl-access = free}}</ref> and that extra stability would be predominantly a consequence of the neutron shell closure.<ref name=not114/> Although known nuclei still fall several neutrons short of ''N''&nbsp;=&nbsp;184 where maximum stability is expected (the most neutron-rich confirmed nuclei, <sup>293</sup>Lv and <sup>294</sup>Ts, only reach ''N''&nbsp;=&nbsp;177), and the exact location of the center of the island remains unknown,<ref name=physorg>{{cite web |url=http://newscenter.lbl.gov/2009/09/24/114-confirmed/ |title=Superheavy Element 114 Confirmed: A Stepping Stone to the Island of Stability |date=2009 |access-date=23 October 2019 |publisher=[[Lawrence Berkeley National Laboratory|Berkeley Lab]]}}</ref><ref name=beachhead /> the trend of increasing stability closer to ''N''&nbsp;=&nbsp;184 has been demonstrated. For example, the isotope <sup>285</sup>Cn, with eight more neutrons than <sup>277</sup>Cn, has a half-life almost five orders of magnitude longer. This trend is expected to continue into unknown heavier isotopes in the vicinity of the shell closure.<ref name=Zagrebaev />

===Deformed nuclei===
[[File:Even Z alpha decay chains.svg|thumb|right|upright=2|alt=A diagram of observed decay chains of even Z superheavy nuclides, consisting of several alpha decays and terminating in spontaneous fission.|A summary of observed decay chains in even-''Z'' superheavy elements, including tentative assignments in chains 3, 5, and 8.<ref name="Hofmann2016" /> According to another analysis, chain 3 (starting at element 120) is not a real decay chain, but is rather a random sequence of events.<ref>{{cite journal |last1=Heßberger |first1=F. P. |last2=Ackermann |first2=D. |date=2017 |title=Some critical remarks on a sequence of events interpreted to possibly originate from a decay chain of an element 120 isotope |journal=The European Physical Journal A |volume=53 |issue=123 |page=123 |doi=10.1140/epja/i2017-12307-5|bibcode=2017EPJA...53..123H |s2cid=125886824 }}</ref> There is a general trend of increasing stability for isotopes with a greater neutron excess (''N''&nbsp;−&nbsp;''Z'', the difference in the number of protons and neutrons), especially in elements 110, 112, and 114, which strongly suggests that the center of the island of stability lies among even heavier isotopes.]]Though nuclei within the island of stability around ''N''&nbsp;=&nbsp;184 are predicted to be [[spherical]], studies from the early 1990s—beginning with Polish physicists Zygmunt Patyk and Adam Sobiczewski in 1991<ref>{{Cite journal|last1=Patyk|first1=Z.|last2=Sobiczewski|first2=A.|date=1991|title=Ground-state properties of the heaviest nuclei analyzed in a multidimensional deformation space|journal=Nuclear Physics A|language=en|volume=533|issue=1|page=150|bibcode=1991NuPhA.533..132P|doi=10.1016/0375-9474(91)90823-O}}</ref>—suggest that some superheavy elements do not have perfectly spherical nuclei.<ref name=structure>{{cite journal |title=Structure of Odd-''N'' Superheavy Elements |journal=Physical Review Letters |volume=83 |issue=6 |pages=1108–1111 |year=1999 |doi=10.1103/PhysRevLett.83.1108 |last1=Ćwiok |first1=S. |last2=Nazarewicz |first2=W. |last3=Heenen |first3=P. H. |bibcode=1999PhRvL..83.1108C }}</ref><ref name=zaioo>{{cite journal |last1=Zagrebaev |first1=V. I. |last2=Aritomo |first2=Y. |last3=Itkis |first3=M. G. |last4=Oganessian |first4=Yu. Ts. |last5=Ohta |first5=N. |display-authors=3 |title=Synthesis of superheavy nuclei: How accurately can we describe it and calculate the cross sections? |date=2001 |journal=Physical Review C |volume=65 |issue=1 |pages=014607-1–014607-14 <!-- Deny Citation Bot-->|doi=10.1103/PhysRevC.65.014607 |bibcode=2001PhRvC..65a4607Z |url=http://nrv.jinr.ru/pdf_file/zaioo.pdf}}</ref> A change in the shape of the nucleus changes the position of neutrons and protons in the shell. Research indicates that large nuclei farther from spherical magic numbers are [[Superdeformation|deformed]],<ref name=zaioo/> causing magic numbers to shift or new magic numbers to appear. Current theoretical investigation indicates that in the region ''Z''&nbsp;=&nbsp;106–108 and ''N''&nbsp;≈&nbsp;160–164, nuclei may be more resistant to fission as a consequence of shell effects for deformed nuclei; thus, such superheavy nuclei would only undergo alpha decay.<ref name="predictions" /><ref name="longlived" /><ref name="nuclear" /> Hassium-270 is now believed to be a doubly magic deformed nucleus, with deformed magic numbers ''Z''&nbsp;=&nbsp;108 and ''N''&nbsp;=&nbsp;162.<ref name=270Hs01>{{Cite journal |first1=J. |last1=Dvořák |first2 =W. |last2= Brüchle |first3= M. |last3= Chelnokov |first4= R. |last4= Dressler |first5= Ch. E. |last5= Düllmann |first6= K. |last6= Eberhardt |first7= V. |last7= Gorshkov |first8= E. |last8= Jäger |first9= R. |last9= Krücken |first10= A. |last10= Kuznetsov |first11= Y. |last11= Nagame |first12= F. |last12= Nebel |first13= Z. |last13= Novackova |first14= Z. |last14= Qin |first15= M. |last15= Schädel |first16= B. |last16= Schausten |first17= E. |last17= Schimpf |first18= A. |last18= Semchenkov |first19= P. |last19= Thörle |first20= A. |last20= Türler |first21= M. |last21= Wegrzecki |first22= B. |last22= Wierczinski |first23= A. |last23= Yakushev |first24= A. |last24= Yeremin
|display-authors=3 |year=2006 |title=Doubly Magic Nucleus {{su|p=270|b=108}}Hs{{su|b=162}} |journal=[[Physical Review Letters]] |volume=97 |issue=24 |pages=242501-1–242501-4 <!-- Deny Citation Bot-->|bibcode=2006PhRvL..97x2501D |doi=10.1103/PhysRevLett.97.242501 |pmid=17280272|url=https://www.dora.lib4ri.ch/psi/islandora/object/psi%3A16351 }}</ref> It has a half-life of 9 seconds.{{NUBASE2020 |ref |page=030001-174–030001-180}} This is consistent with models that take into account the deformed nature of nuclei intermediate between the actinides and island of stability near ''N''&nbsp;=&nbsp;184, in which a stability "peninsula" emerges at deformed magic numbers ''Z''&nbsp;=&nbsp;108 and ''N''&nbsp;=&nbsp;162.<ref name=Moller97>{{cite journal |last1=Möller |first1=P. |last2=Nix |first2=J. R. |title=Stability and Production of Superheavy Nuclei |date=1998 |journal=AIP Conference Proceedings |volume=425 |issue=1 |pages=75 |doi=10.1063/1.55136 |arxiv=nucl-th/9709016|bibcode=1998AIPC..425...75M |s2cid=119087649 }}</ref><ref name=270Hs2020>{{cite journal |last1=Meng |first1=X. |last2=Lu |first2=B.-N. |last3=Zhou |first3=S.-G. |title=Ground state properties and potential energy surfaces of <sup>270</sup>Hs from multidimensionally constrained relativistic mean field model |date=2020 |journal=Science China Physics, Mechanics & Astronomy |volume=63 |issue=1 |pages=212011-1–212011-9 <!-- Deny Citation Bot-->|doi=10.1007/s11433-019-9422-1 |arxiv=1910.10552|bibcode=2020SCPMA..6312011M |s2cid=204838163 }}</ref> Determination of the decay properties of neighboring hassium and seaborgium isotopes near ''N''&nbsp;=&nbsp;162 provides further strong evidence for this region of relative stability in deformed nuclei.<ref name="Cwiok" /> This also strongly suggests that the island of stability (for spherical nuclei) is not completely isolated from the region of stable nuclei, but rather that both regions are instead linked through an isthmus of relatively stable deformed nuclei.<ref name=Moller97 /><ref name=kjmoody>{{cite book |editor-last=Schädel |editor-first=M. |editor-last2=Shaughnessy |editor-first2=D. |title=The Chemistry of Superheavy Elements |year=2014 |edition=2nd |publisher=Springer |page=3 |chapter=Synthesis of Superheavy Elements |last=Moody |first=K. J. |isbn=978-3-642-37466-1}}</ref>