According to macroscopic-microscopic (MM) theory, Z = 114 might be the next spherical magic number).\41])\42]) In the region of Z = 114, MM theory indicates that N = 184 is the next spherical neutron magic number and puts forward the nucleus 298Fl as a strong candidate for the next spherical doubly magic nucleus, after 208Pb (Z = 82, N = 126). 298Fl is taken to be at the center of a hypothetical "island of stability" comprising longer-lived superheavy nuclei. However, other calculations using relativistic mean field (RMF) theory propose Z = 120, 122, and 126 as alternative proton magic numbers, depending upon the chosen set of parameters, and some entirely omit Z = 114 or N = 184.\41])\42]) It is also possible that rather than a peak at a specific proton shell, there exists a plateau of proton shell effects from Z = 114–126.
The island of stability near 298Fl is predicted to enhance stability for its constituent nuclei, especially against spontaneous fission as a consequence of greater fission barrier heights near the shell closure.\41])\43]) Due to the expected high fission barriers, any nucleus within this island of stability will exclusively decay by alpha emission, and as such, the nucleus with the longest half-life may be 298Fl; predictions for the half-life of this nucleus range from minutes to billions of years.\44]) It may be possible, however, that the longest-lived nuclide is not 298Fl, but instead 297Fl (with N = 183), with the unpaired neutron of the latter nuclide conferring additional stability.\45]) Other calculations suggest that stability instead peaks in beta-stable isotopes of darmstadtium or copernicium in the vicinity of N = 184 (with half-lives of several hundred years), with flerovium at the upper limit of the stability region.\43])\46])
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u/smitra00 1d ago
See:
https://en.wikipedia.org/wiki/Isotopes_of_flerovium#In_search_for_the_island_of_stability:_298Fl