Barium (Ba)
Barium (Ba)
The element barium was discovered in 1808.
Barium is found only in combination with other elements. This alkaline earth metal is metallic, soft, and silvery white when pure, resembling calcium. The metal oxidizes easily and must be kept under petroleum or other oxygen-free liquids.
Barium's important compounds are peroxide, chloride, sulfate, carbonate, nitrate, and chlorate. They are found in pigments, paints, X-ray diagnostics, and glassmaking. Other forms are used in oil well drilling fluids, rubber production, rat poison, and pyrotechnics.
Barium compounds that are water or acid soluble are poisonous. Naturally occurring barium is a mixture of seven stable isotopes, and 22 radioactive isotopes are known to exist.