Osmium (Os)

From Wikipedia, the free encyclopediaOsmium (from Greek osme (ὀσμή) meaning "smell") is a chemical element with symbol Os and atomic number 76. It is a hard, brittle, bluish-white transition metal in the platinum group that is found as a trace element in alloys, mostly in platinum ores. Osmium is the densest naturally occurring element, with a density of 22.59 g/cm3.

Osmium in the periodic table

SymbolOs
Atomic number76
Group8
Period6
Blockd
Element categoryTransition Metal

Physical properties

Phase at STPSolid
Density22.59 g/cm3
Atomic weight190.233 u
Melting point3306 K
3032.85 °C
5491.13 °F
Boiling point5285 K
5011.85 °C
9053.33 °F

Atomära egenskaper

Electronegativity (Pauling Scale)2.2
Electron affinity103.99 kJ/mol
Ionization energies
1840 kJ/mol
2 1600 kJ/mol

Electron configuration

Electron configuration1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d6 6s2
Electrons per shell2, 8, 18, 32, 14, 2

History

Discovered1803
Discovered bySmithson Tennant