Symbol Name Atomic Number Atomic Weight Group Number
Ra Radium 88 226.0254 2


Standard State: Solid at 298 K
Color: Metallic

Radium was discovered in 1898 by M. and Mme. Curie in the pitchblende or uraninite of North Bohemia, where it occurs.  There is about 1 g of radium in 7 tons of pitchblende.  The element was isolated in 1911 by Mme. Curie and Debierne by the electrolysis of a solution of pure radium chloride, employing a mercury cathode; on distillation in an atmosphere of hydrogen this amalgam yielded the pure metal. Radium is obtained commercially as the bromide or chloride; it is doubtful if any appreciable stock of the isolated element now exists. The pure metal is brilliant white when freshly prepared, but blackens on exposure to air, probably due to formation of the nitride.  Radium is a radiological hazard and inhalation, injection, or body exposure can cause cancer and other body disorders.