radioactive series

Definition: A series of radioactive nuclides in which each member of the series is formed by the decay of the nuclide before it. The series ends with a stable nuclide. Three radioactive series occur naturally, those headed by thorium-232 (thorium series), uranium-235 (actinium series), and uranium-238 (uranium series). All three series end with an isotope of lead. The neptunium series starts with the artificial isotope plutonium-241, which decays to neptunium-237, and ends with bismuth-209. Also Known As: radio decay series