n. Symbol Os
A bluish-white, hard, brittle and extremely dense metallic element, found in small amounts in osmiridium, nickel, and platinum ores. It is used as a platinum hardener and in making pen points, phonograph needles, instrument pivots, and other wear-resistant items. Atomic number 76; atomic weight 190.2; melting point 3,033°C; boiling point 5,012°C; specific gravity 22.587; valence 2, 3, 4, 6, 8. See Periodic Table.
[From Greek osmē, smell (from the strong odor of osmium tetroxide).]
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