Periodic table / Transition metals
78Platinum
Platinum is a transition metal in group 10, period 6. At 25 °C it is a solid.
- Symbol
- Pt
- Atomic number
- 78 protons in the nucleus
- Standard atomic weight
- 195.08 ± 0.02
- Electron configuration
- [Xe] 4f14 5d9 6s1
- Electrons in each shell
- 2, 8, 18, 32, 17, 1
- Group, period, block
- 10, 6, d
- Family
- Transition metals
- State at 25 °C
- solid
- Electronegativity
- 2.28 (Pauling scale)
- First ionisation energy
- 864.4 kJ/mol (8.95883 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.