Thorium (Th) is a chemical element with atomic number (Z) 90, group n/a, period 7, and atomic weight 232.138. The Thorium (Th) is a silvery white metal which is air-stable and retains its lustre for several months. Thorium oxide has a melting point of 3300°C, the highest of all oxides, used as an alloying element in magnesium. (Refer to the Chemical Element; Periodic Table)
