Iridium
Iridium (铱, symbol Ir) is chemical element number 77, a Transition Metal in period 6, group 9 of the periodic table, with a standard atomic weight of about 192.22. Second-densest element, most corrosion-resistant. Found in meteorites and the K-T boundary layer.
Properties
| Atomic number | 77 |
|---|---|
| Symbol | Ir |
| Atomic mass | 192.22 u |
| Category | Transition Metal |
| Period | 6 |
| Group | 9 |
| Electron configuration | [Xe] 4f¹⁴ 5d⁷ 6s² |
| Electronegativity | 2.2 |
| Covalent radius | 141 pm |
| Density | 22.56 g/cm³ |
| Melting point | 2719 K |
| Boiling point | 4701 K |
| Discovery | Smithson Tennant, 1803 |
Overview
Second-densest element, most corrosion-resistant. Found in meteorites and the K-T boundary layer. Element 77, Iridium (Ir), is a Transition Metal found in period 6, group 9. As a transition metal it commonly shows several oxidation states, forms coloured compounds, and is widely used in catalysts and alloys.
Its electron configuration is [Xe] 4f¹⁴ 5d⁷ 6s², with 2 electrons in the outer shell, and an electronegativity of about 2.2 (Pauling). Around 25 °C it is usually a solid (a very high melting point); it melts near 2719 K (2445.9 °C), boils near 4701 K (4427.9 °C), has a density around 22.56 g/cm³.
In industry and daily life it turns up in Catalysis, Precious Metal and Electronics / Semiconductors. It was first described by Smithson Tennant in 1803. See more trends in the visualization center.
Electron shells
Electrons per shell: 2 · 8 · 18 · 32 · 15 · 2
Main uses
- Catalysis
- Precious Metal
- Electronics / Semiconductors
Hazard
Compounds containing Iridium
No compounds in this knowledge base contain Iridium yet.
Data sources
Atomic mass uses IUPAC (CIAAW) standard atomic weights; the covalent radius is from Cordero et al. (2008). Verify on the RSC Periodic Table, PubChem and Wikipedia. Educational reference only.