nuclide
Technical term in nuclear physics for a distinct atomic species defined by its proton number, neutron number, and energy state.
Measure the half-life of the radioactive nuclide.
This nuclide is stable.
放射性同位体 (radioisotope) is a radioactive isotope, a subset of nuclides that undergo radioactive decay.
radionuclide; radioactive nuclide
Compound of 核 (かく, 'nucleus') and 種 (しゅ, 'species, kind'), a direct translation of the English 'nuclide'.