77 Ir 192.22

Iridium

Transition Metal

Iridium (Ir) is a chemical element with atomic number 77, classified as a transition metal. At room temperature it is a solid. It was discovered in 1803 by Smithson Tennant.

Properties

Atomic number
77
Atomic mass
192.22 u
Category
Transition Metal
Group
9
Period
6
Block
d-block
Electron configuration
[Xe] 4f¹⁴ 5d⁷ 6s²
Phase at STP
Solid
Density
22.56 g/cm³
Melting point
2719 K (2445.8 °C)
Boiling point
4701 K (4427.9 °C)
Electronegativity
2.2
Atomic radius
180 pm
Ionization energy
8.967 eV
Discovery
1803 · Smithson Tennant

Common uses

Spark plugs, crucibles, jewelry, anticancer drugs

Did you know?

Most corrosion-resistant element and linked to dinosaur extinction.