Symbol: Ir

Atomic Number: 77

Atomic Weight: 192.217

Iridium (symbol Ir, atomic number 77) is a chemical element and a slivery-white, brittle, and very hard transition metal. It is the most corrosion-resistant metal, and the second-densest element, belonging to the platinum family. While some halogens and molten salts are corrosive to iridium, it can be flammable and is more reactive when in the form of iridium dust.

Iridium was discovered by Smithson Tennant in 1803, who named the element after the goddess Iris. The scientists who studied it created soluble salts by dissolving the element in a mixture of nitric and hydrochloric acids (aqua regia). The French chemists...Read More