Barium is the fifth element in Group 2 of the periodic table, the alkaline earth elements. Its atomic number is 56, its atomic mass is 137.34, and its chemical symbol is Ba.

Properties

Pure barium is a pale yellow, somewhat shiny, somewhat malleable metal. It has a melting point of about 1,300°F (700°C) and a boiling point of about 2,980°F (1,640°C).

Barium is an active metal that combines easily with oxygen, the halogens, and other non-metals. It also reacts with water and with most acids. It is so reactive that it must be stored under kerosene or some other inert liquid to prevent it from reacting with oxygen and moisture of the air.

Occurrence and Extraction

Barium is the fourteenth most abundant element in the Earth's crust, with abundance estimated at about 0.05%. The most common ores of barium are barite (barium sulfate; BaSO₄) and witherite (barium carbonate...