| From Wikipedia, the free encyclopediaGallium 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). | |||||||||
Gallium in the periodic table | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Symbol | Ga | ||||||||
| Atomic number | 31 | ||||||||
| Group | 13 | ||||||||
| Period | 4 | ||||||||
| Block | p | ||||||||
| Element category | Post-Transition Metal | ||||||||
Physical properties | |||||||||
| Phase at STP | Solid | ||||||||
| Density | 5.91 g/cm3 | ||||||||
| Atomic weight | 69.7231 u | ||||||||
| Melting point | 302.915 K 29.765 °C 85.577 °F | ||||||||
| Boiling point | 2673 K 2399.85 °C 4351.73 °F | ||||||||
Atomic properties | |||||||||
| Electronegativity (Pauling Scale) | 1.81 | ||||||||
| Electron affinity | 41 kJ/mol | ||||||||
| Oxidation states | −5, −4, −3, −2, −1, +1, +2, +3 (an amphoteric oxide) | ||||||||
| Ionization energies |
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Electron configuration | |||||||||
| Elektronkonfiguration (shorthand) | [Ar] 3d10 4s2 4p1 | ||||||||
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p1 | ||||||||
| Electrons per shell | 2, 8, 18, 3 | ||||||||
History | |||||||||
| Discovered | 1875 | ||||||||
| Discovered by | Paul-Émile Lecoq de Boisbaudran | ||||||||