Editing Extended periodic table (section)

==== Unbiquadium (E124) <span class="anchor" id="Unbiquadium"></span> ====
{{Further|Unbiquadium}}
Scientists at [[GANIL]] (Grand Accélérateur National d'Ions Lourds) attempted to measure the direct and delayed fission of compound nuclei of elements with ''Z'' = 114, 120, and 124 in order to probe [[nuclear shell|shell]] effects in this region and to pinpoint the next spherical proton shell. This is because having complete nuclear shells (or, equivalently, having a [[magic number (physics)|magic number]] of [[proton]]s or [[neutron]]s) would confer more stability on the nuclei of such superheavy elements, thus moving closer to the [[island of stability]]. In 2006, with full results published in 2008, the team provided results from a reaction involving the bombardment of a natural [[germanium]] target with uranium ions:

:{{nuclide|uranium|238}} + {{nuclide|germanium|''nat''}} → <sup>308, 310, 311, 312, 314</sup>124* → ''fission''

The team reported that they had been able to identify compound nuclei fissioning with half-lives > 10<sup>−18</sup> s. This result suggests a strong stabilizing effect at ''Z'' = 124 and points to the next proton shell at ''Z'' > 120, not at ''Z'' = 114 as previously thought. A compound nucleus is a loose combination of [[nucleon]]s that have not arranged themselves into nuclear shells yet. It has no internal structure and is held together only by the collision forces between the target and projectile nuclei. 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 potentially be recognised as being discovered. Thus, the GANIL experiments do not count as a discovery of [[element 124]].<ref name="emsley"/>

The fission of the compound nucleus <sup>312</sup>124 was also studied in 2006 at the tandem ALPI heavy-ion accelerator at the [[Laboratori Nazionali di Legnaro]] (Legnaro National Laboratories) in Italy:<ref name="thomas">{{cite journal|last1=Thomas|first1=R.G.|last2=Saxena|first2=A.|last3=Sahu|first3=P.K. |last4=Choudhury|first4=R.K.|last5=Govil|first5=I.M.|last6=Kailas|first6=S. |last7=Kapoor|first7=S.S.|last8=Barubi|first8=M.|last9=Cinausero|first9=M. |last10=Prete|first10=G.|last11=Rizzi|first11=V.|last12=Fabris|first12=D. |last13=Lunardon|first13=M.|last14=Moretto|first14=S.|last15=Viesti|first15=G. |last16=Nebbia|first16=G.|last17=Pesente|first17=S.|last18=Dalena|first18=B. |last19=D'Erasmo|first19=G.|last20=Fiore|first20=E.M.|last21=Palomba|first21=M. |last22=Pantaleo|first22=A.|last23=Paticchio|first23=V.|last24=Simonetti|first24=G. |last25=Gelli|first25=N.|last26=Lucarelli|first26=F.|date=2007|title=Fission and binary fragmentation reactions in <sup>80</sup>Se+<sup>208</sup>Pb and <sup>80</sup>Se+<sup>232</sup>Th systems|journal=Physical Review C|volume=75|issue=2|pages=024604–1–024604–9|doi=10.1103/PhysRevC.75.024604|hdl=2158/776924|hdl-access=free}}</ref>

:{{nuclide|thorium|232}} + {{nuclide|selenium|80}} → <sup>312</sup>124* → ''fission''

Similarly to previous experiments conducted at the JINR ([[Joint Institute for Nuclear Research]]), [[fission product|fission fragments]] clustered around [[doubly magic]] nuclei such as <sup>132</sup>Sn (''Z'' = 50, ''N'' = 82), revealing a tendency for superheavy nuclei to expel such doubly magic nuclei in fission.<ref name="www1.jinr.ru"/> The average number of neutrons per fission from the <sup>312</sup>124 compound nucleus (relative to lighter systems) was also found to increase, confirming that the trend of heavier nuclei emitting more neutrons during fission continues into the superheavy mass region.<ref name=thomas/>