an isotope of lead, formed by decay of radium A, that gives rise to radium C, which is an isotope of bismuth, from which radium D, radium E, and radium F, or polonium 210, are derived.
noun, Chemistry. 1. (formerly) .
noun, Chemistry. 1. an isotope of polonium: polonium 210.
noun, Chemistry. 1. a white, crystalline, water-insoluble, poisonous, radioactive solid, RaSO 4 , used chiefly in radiotherapy.
noun 1. treatment of disease by means of radium. noun 1. treatment of disease, esp cancer, by exposing affected tissues to radiation from radium radium therapy n. The use of radium in radiotherapy.