Atomic Number: 56 Period Number: 6 Group Number: 2
Barium is a soft silvery metallic alkaline earth materials. It exists in nature as compound because it react with oxygen and water. Barium is most commonly found as the mineral barite (BaSO4) and witherite (BaCO3).
Barium is used as a getter, a material that combines with and removes trace gases from vacuum tubes.
Barium sulfate and Barium carbonate are the most common compounds of barium. Barium sulfate is an important parts for white pigment. Although all barium compounds are poisonous, barium sulfate can be safely ingested since it does not dissolve in water and it is also a good absorber of X-rays, so it can be used to produce X-ray images of the intestinal tract.
Physical and Chemical properties:
Atomic Weight: 137.327
Melting Point: 1000 K
Boiling Point: 2170 K
Density: 3.62 g/cm3
Phase at Room Temperature: Solid
Element Classification: Metal
Ionization Energy: 5.212 eV
Oxidation State: +2
Wikipedia - Basics on Barium
WebElements - The basic elements of Barium
Jefferson Lab - Learning about Barium