A whitish, malleable, metallic → chemical element; symbol Ba. → Atomic number 56; → atomic weight 137.33; → melting point 725°C; → boiling point 1,640°C; → specific gravity 3.5 at 20°C. Barium was discovered by the Swedish pharmacist and chemist Carl Wilhelm Scheele in 1774. It was first isolated by the British chemist Humphry Davy in 1808.
From Mod.L., from Gk. barys "heavy," from the mineral barytes "heavy spar" (BaSO4), in which the element was discovered; cognate with Pers. bâr "weight," → bar.
Fr.: étoile à barium
A type of star, usually G or K → giants, whose spectra show unusually strong absorption lines of → barium, → strontium, and other → s-process elements.