Iridium (Ir), element 77 – Learn Acer periodic table

Iridium

Transition metal, atomic number 77.

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

Facts

Symbol Ir. Atomic mass 192.2173 u. Group 9, period 6. Electron configuration [Xe] 4f14 5d7 6s2. Electrons per shell 2, 8, 18, 32, 15, 2. State at room temperature: Solid. Melting point 2445.8 °C, boiling point 4129.9 °C. Discovered by Smithson Tennant.

Element data from Wikipedia, CC BY-SA 3.0.