Iridium

Transition metal · 192.22 u · group 9, period 6

Iridium · Ir

Atomic number77

SymbolIr

CategoryTransition metal

Standard stateSolid

Group · Period · Block9 · 6 · d

Electron configuration[Xe]6s2 4f14 5d7

Atomic mass192.22 u

Atomic radius202 pm

Protons / Neutrons / Electrons77 / 115 / 77

Shells (e⁻ per shell)2, 8, 18, 32, 15, 2

Electronegativity (Pauling)2.2

Ionization energy9.1 eV

Electron affinity1.565 eV

Oxidation states+4, +3

Melting point2.72e+3 K · 2.45e+3 °C

Boiling point4.70e+3 K · 4.43e+3 °C

Density22.42 g/cm³

Year discovered1803

CPK color

#175487

State at room temp (25 °C)

solid

Position