Barium is a chemical element with symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element.

Atomic Weight:  4343
Density:        45.76 g/cm3
Melting Point:  45 °C
 Boiling Point: 6767 °C