Chemical Element: barium

(Modern Latin: chemical element; from Greek, baros, heavy; because its compounds are dense; metal)

Chemical-Element Information

Symbol: Ba
Atomic number: 56
Year discovered: 1808

Discovered by: Sir Humphry Davy (1778-1829), an English chemist.


  • Barium oxidizes very rapidly in air, and reacts readily with water and alcohol.
  • It was first investigated in 1602 by Vincenzo Cascariolo, a shoemaker of Bologna, who found that after ignition with combustible substances, it became phosphorescent, and on this account it was frequently called Bolognian phosphorus.
  • In 1774, K. W. Scheele, in examining a specimen of pyrolusite, found a new substance to be present in the mineral, for on treatment with sulfuric acid it gave an insoluble salt which was afterward shown to be identical with that contained in heavy spar.
  • The metal is difficult to isolate; Sir Humphry Davy tried to electrolyze baryta (barium oxide) but was unsuccessful; later attempts were made by using barium chloride in the presence of mercury.
  • In this way he obtained an amalgam, from which on distilling off the mercury the barium was obtained as a silver white residue.
  • Barium was first isolated by Davy in 1808.
  • It is used in the manufacture of radio vacuum tubes because it removes the final traces of gaseous elements that remain after the tubes have been evacuated almost completely by other methods.

Name in other languages:

French: baryum

German: Barium

Italian: bario

Spanish: bario


Information about other elements may be seen at this Chemical Elements List.

A special unit about words that include chemo-, chem- may be seen here.