Osmium (Os)

Osmium 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.

Atomic Number

76

Atomic Mass

190.23 u

Category

transition metal

Phase

solid

Density

22.59 g/cm³

Electron Shells

2, 8, 18, 32, 14, 2

Atomic Structure

Protons: 76 • Electrons: 76 • Neutrons: Varies by isotope

Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d⁶

Discovery

1803 • Smithson Tennant