Atomic mass
Physical190.23u
Weighted average of the naturally occurring isotopes.
01 / The referenceMeasured to
Measured to
the last atom.
A detailed view of osmium’s physical, thermal, chemical, and electrical profile. Values are representative of pure osmium under standard conditions.
Atomic number76
SymbolOs
Period6
Blockd-block
Density
Physical22.59g/cm³
Measured near room temperature; among the highest densities of any element.
Melting point
Thermal3,033°C
The temperature at which solid osmium becomes liquid at standard pressure.
Boiling point
Thermal5,012°C
High thermal stability makes osmium useful in demanding environments.
Common oxidation states
Chemical+3, +4primary
Osmium forms compounds across a broad range, including the volatile OsO₄.
Electrical resistivity
Physical81.2nΩ·m
Resistance of pure material at 20°C, relevant to precision contacts.
Mohs hardness
Chemical7.0Mohs
A hard, brittle metal with exceptional resistance to wear and deformation.
Crystal structure
PhysicalHCPhexagonal
Atoms arrange in a close-packed hexagonal lattice under ambient conditions.
Reading the data: Scales are visual guides, not direct comparisons between different units.
03 / In contextHow dense is
How dense is
exceptional?
| Material | Density | Relative to osmium | At 20°C |
|---|---|---|---|
| Osmium | 22.59 g/cm³ | 100% | Solid |
| Iridium | 22.56 g/cm³ | 99.9% | Solid |
| Platinum | 21.45 g/cm³ | 94.9% | Solid |
| Lead | 11.34 g/cm³ | 50.2% | Solid |
A careful sourceData with a
Data with a
clear provenance.
Figures are compiled from standard reference tables and reviewed for consistency. Explore the notes behind each value, or download a concise version for your lab or classroom.
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