31Ga69.723
Post-Transition Metalp-block
Gallium
Element 31 on the periodic table, symbol Ga, group 13, period 4.
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).
Appearance: silver-white
Properties
- Atomic Number
- 31
- Atomic Mass
- 69.7231 u
- Group
- 13
- Period
- 4
- Block
- p-block
- Category
- Post-Transition Metal
- State at 25 °C
- Solid
- Melting Point
- 302.9 K · 29.8 °C
- Boiling Point
- 2,673 K · 2,399.9 °C
- Density
- 5.91 g/cm³
- Atomic Radius
- 130 pm
- Electronegativity
- 1.81
- Oxidation States
- +3
- Abundance in Crust
- 19 mg/kg
- Discovered
- 1875
- Discovered By
- Lecoq de Boisbaudran
Electron Configuration
[Ar] 3d10 4s2 4p1
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p1
Ionisation Energies (kJ/mol)
- 1. 578.8
- 2. 1,979.3
- 3. 2,963
- 4. 6,180
Elements near Gallium
Elements in the same group share the number of outer electrons and behave in similar ways. Elements in the same period share a shell, so they change steadily from left to right.