|a brittle hard silvery-white element that is a ferromagnetic metal: occurs principally in cobaltite and smaltite and is widely used in alloys. The radioisotope cobalt-60, with a half-life of 5.3 years, is used in radiotherapy and as a tracer. Symbol: Co; atomic no: 27; atomic wt: 58.93320; valency: 2 or 3; relative density: 8.9; melting pt: 1495°C; boiling pt: 2928°C|
|[C17: German Kobalt, from Middle High German kobolt goblin; from the miners' belief that malicious goblins placed it in the silver ore]|
cobalt co·balt (kō'bôlt')
A metallic element, used chiefly for magnetic and high-temperature alloys and in the form of its salts for blue glass and ceramic pigments. Atomic number 27; atomic weight 58.9332; melting point 1,495°C; boiling point 2,930°C; specific gravity 8.9; valence 2, 3.
|cobalt (kō'bôlt') Pronunciation Key
A silvery-white, hard, brittle metallic element that occurs widely in metal ores. It is used to make magnetic alloys, heat-resistant alloys, and blue pigment for ceramics and glass. Atomic number 27; atomic weight 58.9332; melting point 1,495°C; boiling point 2,900°C; specific gravity 8.9; valence 2, 3. See Periodic Table.