Radium is a chemical element with symbol Ra and atomic number 88. It is the sixth element in Group 2 of the periodic table. Pure Ra is silvery-white in color, but it combines with nitrogen readily on exposure to air and forms a black surface layer of radium nitride. It was discovered by Marie Sklodowska Curie and Perre Curie in 1898, in the form of radium chloride. They extracted the radium compound from uraninite. It is found in uranium ores at 1 part per 3 million parts uranium.
|Atomic Mass||226 g.mol −1|
|Discovered by||Marie Sklodowska Curie and Perre Curie in 1898|
It was isolated in its metallic state by Marie Curie and André-Louis Debierne through the electrolysis of radium chloride in 1911. In nature, It was found in uranium and (to a lesser extent) thorium ores in trace amounts as small as a seventh of a gram per ton of uraninite. It is not necessary for living organisms, and adverse health effects are likely when it is incorporated into biochemical processes because of its radioactivity and chemical reactivity. Currently, other than its use in nuclear medicine, It has no commercial applications; formerly, it was used as a radioactive source for radioluminescent devices and also in radioactive quackery for its supposed curative powers. Today, these former applications are no longer in vogue because radium’s toxicity has become known, and less dangerous isotopes are used instead in radioluminescent devices.