Precious Metal Elements
Iridium［ Atomic number77 Atomic weight192.217 ］
Used for vehicle spark plugs because of excellent hardness and corrosion resistance, and for the crucibles used to manufacture sapphire substrates for LEDs because of high heat resistance.
The other day, my buddy Platinum set the sauna temperature too high and went all limp, but I went to his rescue. My job is to work in harsh environments. Hey, I’m resistant to electric shock as well!
| Ir | Iridium | |
|---|---|---|
| Atomic number | 77 | |
| Atomic weight | 192.217 | |
| Isotope | 191Ir, 193Ir | |
| Crystal Structure | fcc | |
| Metallicity | Trans.Metal | |
| Shell | 2,8,18,32,15,2 | |
| Filling Orbital | 5d7 | |
| Oxidation States | 2,3,4,6 | |
| Atomic Radius | Å | 1.87 |
| Covalent Radius | Å | 1.36 |
| Atomic Volume | cm3/mol | 8.54 |
| Density at 293K | g/cm3 | 22.42 |
| Melting Point | ℃ | 2446 |
| Boiling Point | ℃ | 4437 |
| Specific Heat | J/gK | 0.130 |
| Heat of Fusion | kJ/mol | 26.10 |
| Heat of Vaporization | kJ/mol | 604.0 |
| Thermal Conductivity at 273K | W/mK | 147 |
| Specific Resistance at 273K | 10-6 Ωcm | 4.7 |
| Coefficient of Linear expansion at 293K | 10-6 K-1 | 6.4 |
| Ionization Potential | V | 8.96702 |
| 2nd Ionization Potential | V | |
| Electron Affinity | eV | 1.5638 |
| Electronegativity | 2.2 | |
| Discovery | year | 1804 |