A nuclide (or nucleide, from nucleus, also known as nuclear species) is a class of atoms characterized by their number of protons, Z, their number of neutrons...

– noting also the primordial radionuclide 87Rb) and 82 (six: 138Ba, 139La, 140Ce, 141Pr, 142Nd, 144Sm – noting also the primordial radionuclide 136Xe)...

ionization chambers of most modern smoke detectors. Of the actinides, primordial thorium and uranium occur naturally in substantial quantities. The radioactive...