Periodic table / Transition metals
76Osmium
Osmium is a transition metal in group 8, period 6. At 25 °C it is a solid.
- Symbol
- Os
- Atomic number
- 76 protons in the nucleus
- Standard atomic weight
- 190.23 ± 0.03Some geological samples have an unusual isotope mix, so their atomic weight can fall outside this range.
- Electron configuration
- [Xe] 4f14 5d6 6s2
- Electrons in each shell
- 2, 8, 18, 32, 14, 2
- Group, period, block
- 8, 6, d
- Family
- Transition metals
- State at 25 °C
- solid
- Electronegativity
- 2.2 (Pauling scale)
- First ionisation energy
- 814.2 kJ/mol (8.43823 eV)
Where these numbers come from
Atomic weight: IUPAC CIAAW, abridged standard atomic weights 2024. Electron configuration and ionisation energy: NIST Atomic Spectra Database. Family, state and electronegativity: PubChem. See Sources. Melting points, boiling points and densities are left out for now: published values differ between sources, and we will add them once each has been checked.