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Periodic table / Transition metals

77Iridium

Iridium is a transition metal in group 9, period 6. At 25 °C it is a solid.

Ir
Shells: 2, 8, 18, 32, 15, 2. A simple picture: electrons do not move in circles.
Symbol
Ir
Atomic number
77 protons in the nucleus
Standard atomic weight
192.22 ± 0.01
Electron configuration
[Xe] 4f14 5d7 6s2
Electrons in each shell
2, 8, 18, 32, 15, 2
Group, period, block
9, 6, d
Family
Transition metals
State at 25 °C
solid
Electronegativity
2.2 (Pauling scale)
First ionisation energy
865.2 kJ/mol (8.96702 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.