barium 140: Meaning and Definition of

barium 140

Pronunciation: [key]
— Chem. Chem.
  1. the radioactive isotope of barium having a mass number of 140 and a half-life of 12.8 days, used chiefly as a tracer.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.