Compare Gold vs Iridium
Comparing Gold (Au) and Iridium (Ir). Atomic numbers 79 and 77 with atomic masses 196.967 u and 192.217 u, classified as transition metal and transition metal. Below: a side-by-side comparison of their physical, atomic, electron-configuration and historical properties, including density, melting and boiling points, ionization energies, oxidation states and discovery history.
Periodic properties of the elements
| Gold | Iridium | |
|---|---|---|
| Symbol | Au | Ir |
| Atomic number | 79 | 77 |
| Group | 11 | 9 |
| Period | 6 | 6 |
| Block | d | d |
| Element category | Transition Metal | Transition Metal |
Physical properties
| Gold | Iridium | |
|---|---|---|
| Phase at STP | Solid | Solid |
| Density | 19.3 g/cm3 | 22.56 g/cm3 |
| Atomic weight | 196.967 u | 192.217 u |
| Melting point | 1337.33 K 1064.18 °C 1947.524 °F | 2719 K 2445.85 °C 4434.53 °F |
| Boiling point | 3243 K 2969.85 °C 5377.73 °F | 4403 K 4129.85 °C 7465.73 °F |
Atomic properties
| Gold | Iridium | |
|---|---|---|
| Electronegativity (Pauling Scale) | 2.54 | 2.2 |
| Electron affinity | 222.747 kJ/mol | 150.94 kJ/mol |
| Oxidation states | −3, −2, −1, 0, +1, +2, +3, +5 (an amphoteric oxide) | −3, −1, 0, +1, +2, +3, +4, +5, +6, +7, +8, +9 () |
| Ionization energies |
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Electron configuration
| Gold | Iridium | |
|---|---|---|
| Shorthand configuration | [Xe] 4f14 5d10 6s1 | [Xe] 4f14 5d7 6s2 |
| Full configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s1 | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d7 6s2 |
| Electrons per shell | 2, 8, 18, 32, 18, 1 | 2, 8, 18, 32, 15, 2 |
History
| Gold | Iridium | |
|---|---|---|
| Discovery | Levant (6000 BC) | Smithson Tennant (1803) |
| First isolation | Smithson Tennant (1803) |