Symbol Ir
Atomic Number 77
Atomic Mass 192.217
Discovered by Ghiorso in 1952

Chemical Properties of Iridium

Group 9 Melting point 2446°C, 4435°F, 2719 K
Period 6 Boiling point 4428°C, 8002°F, 4701 K 
Block d Density (g cm−3) 22.5622 
Atomic number 77 Relative atomic mass 192.217
State at 20°C Solid Key isotopes 193Ir 
Electron configuration [Xe] 4f145d76s2  CAS number 7439-88-5
ChemSpider ID 22367 ChemSpider is a free chemical structure database

What is Iridium?

  • Iridium is a transition metal of the platinum family with symbol Ir and atomic number 77 in the periodic table.
  • Iridium is a hard, lustrous, brittle, dense transition metal of the platinum family.

Physical properties of Iridium

  • It is silverish-white and it is known to be the most corrosion resistant element known. It is unaffected by air, water, and acids.
  • It is one of the lesser known members of the platinum group, iridium possesses quite remarkable physical and chemical properties.
  • Not only is the most corrosion resistant of all metals, it is insoluble in all mineral acids at high temperatures, but has a very high melting point and is the only metal that can maintain good mechanical properties in air temperatures above 1600°C.
  • It has a high modulus of rigidity and elasticity.

Applications and effects of Iridium

  • Nowadays the automotive industry, chemical industry and electronic industry, have the most demand for iridium, where it is used to coat the electrodes in the chlor-alkali process, and in catalyst.
  • Some applications are in pivot bearings and in scientific and other special equipment, but it is principally used in alloys: osmium/iridium alloys are used for tipping fountain pen nibs and for compass bearings.
  • It is also known to be used in Space vehicles and Satellites.

Practise This Question

The process of taking out threads from the cocoon for use as silk is called ________