barium (Ba)
A soft, silvery-white metallic element that
readily tarnishes in air. Barium is one of the alkaline
earth metals. It was discovered by Humphry Davy
in 1808 and occurs chiefly as barite (barium
sulfate, BaSO4) and as witherite (barium carbonate, BaCO3).
The compounds of barium resemble those of calcium
but are poisonous. They are used in the manufacture of paints, glass,
rodent poison, and fireworks, and as drying
agents. Barium sulfate is swallowed to allow X-ray
examination of the stomach and intestines
because barium atoms are opaque to X-rays;
this is called a "barium meal." The most common isotope
is barium-138 (71.66 percent).
| atomic number |
56 |
| relative atomic mass |
137.34 |
| relative density |
3.51 |
| melting point |
725°C (1,337°F) |
| boiling point |
1,640°C (2,984°F) |
Related category
INORGANIC
CHEMISTRY
Also on this site: Encyclopedia
of Alternative Energy & Sustainable Living
Encyclopedia
of History
BACK TO TOP
|