barium
钡,钡剂,钡质,钡元素
Definitions
- 1
Chemistry.
- : a whitish, malleable, active, divalent, metallic element, occurring in combination chiefly as barite or as witherite. Symbol: Ba; atomic weight: 137.34; atomic number: 56; specific gravity: 3.5 at 20°C.
Examples
His case hinged on evidence that his hands tested positive for gunshot residue — microscopic particles of lead, barium and other metals discharged during gunfire.
The results of the experiments were puzzling at first, but when Hahn and Strassmann reported to Meitner that barium, a much lighter element than uranium, was a product of the reaction, it became clear what was happening.
Those wells contained mercury, boron, calcium, sulfate and barium — all of which are potential indicators of coal ash contaminants.
Barium and sodium salts were made by neutralizing the acid, and were purified by crystallization.
It was then evaporated to a small bulk, neutralized with barium carbonate and extracted with ether.
The excess of lead was removed by sulphuric acid, and the sulphuric acid was removed by barium carbonate.
By warming with alkalies or barium hydroxide, rhamnose is colored yellow.
The described change in ionization can be roughly followed with the aid of an insoluble sulphate like barium sulphate.