31Ga69.723
Gallium
Post-Transition Metal
Solid at STP
Period 4Group 13Block PDiscovered 1875
[Ar]4s2 3d10 4p1
Gallium is a chemical element with symbol Ga and atomic number 31. Elemental gallium does not occur in free form in nature, but as the gallium(III) compounds that are in trace amounts in zinc ores and in bauxite. Gallium is a soft, silvery metal, and elemental gallium is a brittle solid at low temperatures, and melts at 29.76 °C (85.57 °F) (slightly above room temperature).
📖 Read more on Wikipedia →Atomic Properties
| Atomic Number | 31 |
| Atomic Mass | 69.723 u |
| Electron Configuration | [Ar]4s2 3d10 4p1 |
| Oxidation States | +3 |
| Electronegativity | 1.81 (Pauling) |
| Atomic Radius | 187 pm |
| Ionization Energy | 5.999 eV |
| Electron Affinity | 0.3 eV |
| Block | P |
Physical Properties
| Appearance | silver-white |
| Standard State | Solid |
| Melting Point | 302.91 K (29.8 °C) |
| Boiling Point | 2477 K (2203.8 °C) |
| Density | 5.91 g/cm³ |
| Molar Heat | 25.86 J/(mol·K) |
| CPK Color | #C28F8F |
Classification
| Category | Post-Transition Metal |
| Group Block | Post-transition metal |
| Period | 4 |
| Group | 13 |
| Block | P |
Discovery
| Year Discovered | 1875 |
| Discovered By | Lecoq de Boisbaudran |
| Electron Shells | 2, 8, 18, 3 |