Osmium (Os)

Osmium (Os) is element 76, a transition metal. Atomic mass 190.23, configuration [Xe] 4f¹⁴ 5d⁶ 6s². Properties, isotopes, oxidation states, uses and history, with an interactive 3D atom model.

Open Osmium in the interactive periodic table

Key facts

Atomic number76
SymbolOs
Standard atomic weight190.23(3)
CategoryTransition Metal
Group8
Period6
State at room temperatureSolid
Electron configuration[Xe] 4f¹⁴ 5d⁶ 6s²
Valence electrons2 (Variable)
Common oxidation states+4
Common ionsNo common ions
Electronegativity (Pauling)2.2
First ionization energy840 kJ/mol
Electron affinity106.1 kJ/mol
Atomic radius130 pm
Density22.59 g/cm³
Melting point3055°C
Boiling point5012°C
Specific heat0.13 J/(g·°C)

Natural isotopes

Common uses

Where it matters

Hazards

History

Discovered1803
Discovered bySmithson Tennant
NameFrom Greek osme (smell)