Meaning of radioactive series

ra'dioac'tive se'ries

Pronunciation: [key]
— Physics, Chem. Physics,Chem.
  1. a succession of elements initiated in the radioactive decay of a parent, as thorium or uranium, each of which decays into the next until a stable element, usually lead, is produced. Also called
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.