Discoverd by C. Perrier and E. G. Segre at Palermo, Italy.
Remarks
Radioactive metal which does not occur naturally. Silvery as the metal but usually obtained as a gray powder. Resists oxidation, slowly tanishes in moist air, burns in oxygen, dissolves in nitric and sulfuric acids.
References
Emsley, J., 1991; THE ELEMENTS : Sec. Ed.,
Clarendon Press, Oxford, 251 p.