Iridium (Ir)
Iridium is the most corrosion-resistant metal and the second densest element. A layer of iridium in rock marks the asteroid that killed the dinosaurs.
Properties of Iridium
- Atomic number
- 77
- Category
- Transition Metal
- Atomic mass
- 192.22 u
- Electron configuration
- [Xe] 4f¹⁴ 5d⁷ 6s²
- Melting point
- 2719 K (2445.85 °C)
- Boiling point
- 4701 K (4427.85 °C)
- Density
- 22.56 g/cm³
- Electronegativity (Pauling)
- 2.2
- Appearance
- Silvery-white metal
- Discovered by
- Smithson Tennant (1803)
Facts about Iridium
- A thin layer of iridium in rocks is evidence that an asteroid wiped out the dinosaurs!
- Iridium is named after Iris, the Greek goddess of rainbows, for its colorful compounds!
- Iridium is the most corrosion-resistant metal known!
- The kilogram used to be defined by a platinum-iridium bar kept in Paris!