Gallium (Ga)
Gallium (Ga) is element 31, a post-transition metal. Atomic mass 69.723, configuration [Ar] 3d¹⁰ 4s² 4p¹. Properties, isotopes, oxidation states, uses and history, with an interactive 3D atom model.
Key facts
| Atomic number | 31 |
|---|---|
| Symbol | Ga |
| Standard atomic weight | 69.723(1) |
| Category | Post-transition Metal |
| Group | 13 |
| Period | 4 |
| State at room temperature | Solid |
| Electron configuration | [Ar] 3d¹⁰ 4s² 4p¹ |
| Valence electrons | 3 |
| Common oxidation states | +3 |
| Common ions | No common ions |
| Electronegativity (Pauling) | 1.81 |
| First ionization energy | 579 kJ/mol |
| Electron affinity | 41.49 kJ/mol |
| Atomic radius | 136 pm |
| Density | 5.91 g/cm³ |
| Melting point | 29.76°C |
| Boiling point | 2204°C |
| Specific heat | 0.373 J/(g·°C) |
Natural isotopes
- Ga-69: Stable
- Ga-71: Stable
Common uses
- Blue/Violet LEDs (GaN)
- Integrated circuits
- High-temp thermometers
Where it matters
- Semiconductor physics (LEDs/Lasers)
- Mendeleev's 'Eka-aluminum'
Hazards
- Corrosive to aluminum (liquid metal embrittlement)
History
| Discovered | 1875 |
|---|---|
| Discovered by | Paul-Émile Lecoq de Boisbaudran |
| Name | Lecoq de Boisbaudran (Gallia/France) |