77 Ir 192.217

Iridium

transition metal

Properties

Atomic number
77
Atomic mass
192.217 u
Category
transition metal
Group
9
Period
6
Block
d-block
State (room temp)
Solid
Outer-shell electrons
2
Electronegativity
2.2 (Pauling)
Density
22.56 g/cm³
Melting point
2445.85 °C
Boiling point
4129.85 °C

Electron configuration

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d⁷

Noble-gas shorthand: [Xe] 4f¹⁴ 5d⁷ 6s²

Electrons per shell: 2, 8, 18, 32, 15, 2 — that's 2 in the outermost shell.

See how electron configuration is built →

Ir
Bohr model — outer-shell electrons in blue

About Iridium

Iridium is a chemical element with symbol Ir and atomic number 77. A very hard, brittle, silvery-white transition metal of the platinum group, iridium is generally credited with being the second densest element (after osmium) based on measured density, although calculations involving the space lattices of the elements show that iridium is denser. It is also the most corrosion-resistant metal, even at temperatures as high as 2000 °C. Although only certain molten salts and halogens are corrosive to solid iridium, finely divided iridium dust is much more reactive and can be flammable.

Position in the periodic table

Open the interactive periodic table →

Data compiled from Wikipedia, PubChem, and IUPAC. Source.