Osmium

General properties
Name, symbol, number	osmium, Os, 76
Element category	transition metal
Group, period, block	8, 6, d
Standard atomic weight	190.23
Electron configuration	[Xe] 4f14 5d6 6s2 2, 8, 18, 32, 14, 2
History
Discovery	Smithson Tennant (1803)
First isolation	Smithson Tennant (1803)

Osmium is a chemical element with the symbol Os and atomic number 76. It is a hard, brittle, blue-gray or blue-black transition metal in the platinum family and is the densest naturally occurring element, with a density of 22.59 g/cm³ (slightly greater than that of iridium and twice that of lead). It is found in nature as an alloy, mostly in platinum ores; its alloys with platinum, iridium, and other platinum group metals are employed in fountain pen tips, electrical contacts, and other applications where extreme durability and hardness are needed.

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