31 - Gallium post-transition metal
Discovered by Lecoq de Boisbaudran in 1875
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).
Periodic table
| Shell | Electrons | Orbitals |
|---|---|---|
| 1 | 2 | 2 in 1s |
| 2 | 8 | 2 in 2s + 6 in 2p |
| 3 | 18 | 2 in 3s + 6 in 3p + 10 in 3d |
| 4 | 3 | 2 in 4s + 1 in 4p |
Electron shells
silver-white Appearance
69.7 u Atomic Mass
1.3 Å Atomic Radius
2.48k K Boiling Point
13 Group
3 Common Oxidation States
1.22 Å Covalent Radius
5.91 g/cm³ Density
41 kJ/mol Electron Affinity
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p1 Electron Configuration
[Ar] 3d10 4s2 4p1 Electron Configuration (semantic)
1.81 Electronegativity
31 Electrons
6 eV First Ionization Energy
2, 3 ICSD Oxidation States
578.8, 1979.3, 2963, 6180 kJ/mol Ionization Energies
303 K Melting Point
81 Mendeleev Number
25.9 J/(mol·K) Molar Heat
4 Number of Shells
3 Electron Valency
39 Neutrons
31 Atomic Number
14 Number of Isotopes
1, 2, 3 Oxidation States
4 Period
Solid Phase
31 Protons
2, 8, 18, 3 Electron Shell Occupations
0.371 J/(g K) Specific Heat