Calcium-48

Since ⁴⁸Ca is both practically stable and neutron-rich, it is a valuable starting material for the production of new nuclei in particle accelerators, both by fragmentation and by fusion reactions with other nuclei, for example in the discoveries of the five heaviest known elements, from flerovium to oganesson (atomic numbers 114 through 118). Heavier nuclei generally require a greater fraction of neutrons for maximum stability, so neutron-rich starting materials are necessary.

⁴⁸Ca is the lightest nucleus known to undergo 2β and the only one simple enough to be analyzed with the sd nuclear shell model. It also releases more energy (4.27 MeV) than any other 2β candidate. These properties make it a probe of nuclear structure models and a promising candidate in the ongoing search for neutrinoless double beta decay.