A naturally occurring alkaline metalloid element with atomic symbol Ba, atomic number 56, and atomic weight 137 that is only found in combination with other elements, typically barite (barium sulfate) and witherite (barium carbonate), or chemicals. Barium is used in many industrial processes, as well as in diagnostic testing, fireworks, and pesticides. It is characterized as a silvery white or yellow to white metallic solid that is odorless. Exposure occurs by inhalation, ingestion, or contact.

Alkaline earth element, atomic symbol Ba, atomic number 56, and atomic weight 138; all of its acid-soluble salts are poisonous.

An element of the alkaline earth group of metals. It has an atomic symbol Ba, atomic number 56, and atomic weight 138. All of its acid-soluble salts are poisonous.