Category:Thorium

Tho"ri*um, n. Etym: [nl. See thorite.] (chem.)

Defn: a metallic element found in certain rare minerals, as thorite, Pyrochlore, monazite, etc., and isolated as an infusible gray Metallic powder which burns in the air and forms thoria; -- formerly Called also thorinum. Symbol th. Atomic weight 232.0.