Periodic table / Iridium

Overview

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.

Electron configuration

The electron configuration of Iridium is [Xe] 4f14 5d7 6s2, with electron shells of 2, 8, 18, 32, 15, 2.

Physical and chemical properties

Iridium is classified as a transition metal. It has an atomic mass of 192.217 and exists as a solid at standard conditions, appearing as silvery white.

Real-world uses of Iridium

Although only certain molten salts and halogens are corrosive to solid iridium, finely divided iridium dust is much more reactive and can be flammable.

Interesting facts about Iridium

• Iridium has the atomic number 77 and chemical symbol Ir.
• It belongs to period 6, group 9 of the periodic table.
• Iridium was discovered by Smithson Tennant.

Explore Iridium interactively

Want to compare Iridium with other elements or see it highlighted on the full table? Open the interactive periodic table and click on Ir to explore properties, trends, and neighboring elements. You can also test your knowledge with our periodic table quiz game.