(So named (
Greek osme,
odor) in
1804 by
S. Tennant,
English chemist because of the odor of one of its
oxides) A very hard, bluish-white,
amorphous,
metallic chemical element, one of the
platinum metals. It occurs in the form of an
alloy with
platinum and
iridium and is used in
pen points,
electric light filaments, etc. and as a
catalyst.
Symbol: Os
Atomic number: 76
Atomic weight: 190.23
Density (at room temperature and pressure): 22.59 g/cc
Melting point: 3,000°C
Boiling point: 5,000°C
Valence: +3, +4
Ground state electron configuration: [Xe]4f145d66s2