Iridium - ASCII Periodic Table of the Elements

ASCII PERIODIC TABLE OF THE ELEMENTS

  Ir

Relative atomic mass: 192.217 ± 0.003

English: Iridium
French: Iridium
Croatian: Iridij
German: Iridium
Italian: Iridio
Spanish: Iridio

Atomic number: 77
Group numbers: 9
Period: 6
Standard state (20 °C): solid

Discovery: 1803 Smithson Tennant (GB)

Iridium was discovered by Smithson Tennant (GB) in 1803. The origin of the name comes from the Latin word 'iris', meaning 'rainbow', because its salts are highly coloured. It is a heavy, brittle, white metal that is unreactive in air, water and acids but reacts with fused NaOH. Metal ignites and burns readily. Iridium is found in gravel deposits with platinum. It is used with osmium to tip gold pen points, to make crucible and special containers, also to make alloys used for standard weights and measures and heat-resistant alloys. It is used as a hardening agent for platinum.

Electronic configuration: [Xe] 4f¹⁴ 5d⁷ 6s²
Formal oxidation number: +3 +4
Atomic radius: 135.7 pm

Electronegativities: 2.2
Thermal conductivity: 147 W/(m K)
Electrical resistivity (20 °C): 5.3 μΩcm

Melting point: 2446 °C
Boiling point: 4428 °C

Heat of fusion: 26.4 kJ/mol
Heat of vaporization: 612.1 kJ/mol
Heat of atomization: 664.34 kJ/mol