Wikipedia:Today's featured article/March 21, 2020

Island of stability (circled in white)
Predicted upper region of the chart of nuclides (island of stability circled); darker shades indicate longer half-lives.

The island of stability in nuclear physics is a predicted set of isotopes of superheavy elements whose half-lives may be considerably longer than those experimentally observed for these elements. Its theoretical existence is attributed to stabilizing effects of closed nuclear shells and magic numbers of protons and neutrons. The island of stability is generally thought to center near copernicium and flerovium isotopes with around 184 neutrons, separated from known stable and long-lived nuclides. While stabilizing effects are expected to be greatest for nuclides with around 114 protons, other islands of stability might also exist around heavier nuclides with higher magic numbers. Estimates of the stability of elements on the island are usually around a half-life of minutes or days, with some estimates of up to millions of years. The synthesis of nuclides with up to 118 protons and 177 neutrons has demonstrated a slight stabilizing effect supporting the island's existence. (Full article...)