ra|di|um

ra|di|um «RAY dee uhm», noun.

a radioactive metallic chemical element found in very small amounts in uranium ores such as pitchblende. Radium is very unstable and gives off alpha particles and gamma rays as it breaks down in successive forms into radon, polonium, and, finally, lead. Radium is used in treating cancer and in making luminous paint. »

Radium is never found free, but it is found combined in almost all rocks in extremely minute quantities (Monroe M. Offner).

╂[< New Latin radium < Latin radius ray, beam]