Strontium
Pronunciation : Stron"ti*um
Part of Speech : n.
Etymology : [NL. See Strontia.] (Chem.)
Definition : Defn: A metallic element of the calcium group, always naturally occurring combined, as in the minerals strontianite, celestite, etc. It is isolated as a yellowish metal, somewhat malleable but harder than calcium. It is chiefly employed (as in the nitrate) to color pyrotechnic flames red. Symbol Sr. Atomic weight 87.3. A radioactive isotope of strontium produced by certain nuclear reactions, and constituting one of the prominent harmful components of radioactive fallout from nuclear explosions; also called radiostrontium. It has a half-life of 28 years.
Source : Webster's Unabridged Dictionary, 1913