DefinitionA <THORIUM> is an <Atom> and a <CHEMICAL ELEMENT> with symbol Th and atomic number 90. It is a radioactive actinide metal and a primordial element
Grayish-white lustrous, radioactive metal. Somewhat ductile and malleable. On heating burns in air with formation of the oxide. Standard state: solid Colour: silvery white Discoverer: Jons Berzelius Date discovered: 1815
