BRANCHING

radioactive disintegration of a particular species of unstable atomic nucleus that occurs by two or more different decay processes. Some nuclei of a given radioactive species may, for example, decay by ejecting an electron (negative beta decay) and the rest by ejecting an alpha particle (alpha decay). Thus 99+ percent of any collection of atoms of bismuth-214 decay to polonium-214 by ejecting electrons, while the rest (0.021 percent) decay to thallium-210 by ejecting alpha particles.