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In nuclear physics, the island of stability is a predicted set of isotopes of superheavy elements that may have considerably longer half-lives than known isotopes of these elements. It is predicted to appear as an "island" in the chart of nuclides , separated from known stable and long-lived primordial radionuclides .
Unbihexium has attracted attention among nuclear physicists, especially in early predictions targeting properties of superheavy elements, for 126 may be a magic number of protons near the center of an island of stability, leading to longer half-lives, especially for 310 Ubh or 354 Ubh which may also have magic numbers of neutrons.
The island of stability is a region outside the valley of stability where it is predicted that a set of heavy isotopes with near magic numbers of protons and neutrons will locally reverse the trend of decreasing stability in elements heavier than uranium.
It is predicted that the heavy isotopes 291 Cn and 293 Cn may have half-lives longer than a few decades, for they are predicted to lie near the center of the theoretical island of stability, and may have been produced in the r-process and be detectable in cosmic rays, though they would be about 10 −12 times as abundant as lead. [80]
Later work suggests the islands of stability around hassium and flerovium occur because these nuclei are respectively deformed and 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). [65]
No elements with atomic numbers above 82 (after lead) have stable isotopes. [67] Nevertheless, for reasons not yet well understood, there is a slight increase of nuclear stability around atomic numbers 110–114, which leads to the appearance of what is known in nuclear physics as the "island of stability".
A chart of heavy nuclides with their known and predicted half-lives (known nuclides shown with borders). Nihonium (row 113) is expected to be within the "island of stability" (white circle) and thus its nuclei are slightly more stable than would otherwise be predicted; the known nihonium isotopes are too neutron-poor to be within the island.
This is an accepted version of this page This is the latest accepted revision, reviewed on 9 January 2025. Hypothetical chemical element, symbol Uue and atomic number 119 Chemical element with atomic number 119 (Uue) Ununennium, 119 Uue Theoretical element Ununennium Pronunciation / ˌ uː n. uː n ˈ ɛ n i ə m / ⓘ (OON -oon- EN -ee-əm) Alternative names element 119, eka-francium ...