Gallium
Soft silvery metallic element, belongs to group 13 of the periodic table. The two stable isotopes are Ga-69 and Ga-71. Eight radioactive isotopes are known, all having short half-lives. Gallium Arsenide is used as a semiconductor. Corrodes most other metals by diffusing into their lattice. First identified by Francois Lecoq de Boisbaudran in 1875.
Gallery
Hi-Res Images ofChemical Elements, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons, source: https://images-of-elements.com/gallium.php
Physical Propertiesmass · density · phase · crystal
Atomic Mass
69.7230Da
Density
5.9100g/cm³
Phase (STP)
Solid
Melting Point
302.9K
Boiling Point
2502.2K
Molar Heat
0.3730J/(mol·K)
Crystal Structure
ORC
Lattice Constant
4.510Å
Atomic Radiiatomic · covalent · van der Waals
Atomic (Empirical)
130.00pm
Covalent
124.00pm
Van der Waals
187.00pm
Electronic Propertieselectronegativity · ionization · affinity
Electron Configuration
[Ar] 3d10 4s2 4p
Electron Shells
2, 8, 18, 3
Electronegativity
1.81Pauling
Electron Affinity
0.4kJ/mol
1st Ionization Energy
6.0kJ/mol
Oxidation States
+1, +2, +3
Orbital DiagramAufbau · Hund's rule · Pauli exclusion
Full: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p1Short: [Ar] 3d10 4s2 4p
Ionization Energies (31 known)
Emission Spectrumvisible range · characteristic spectral lines
Abundanceby mass
Log scale · ppm = parts per million by mass
Biological Role
No known biological role. Gallium-67 used in medical imaging.
Discovery
Discovered By
Paul Émile Lecoq de Boisbaudran
Named By
—
Year
1875
Nuclear Data
Known Isotopes
33
Stable Isotopes
7
Stable Mass Numbers
56, 57, 58, 59, 69, 71, 88
Natural isotopic abundance (IUPAC recommended values)
Isotopes of Ga33 known
| Nuclide | Z | N | Mass (AMU) | Half-life | Decay | Jπ | Abundance |
|---|---|---|---|---|---|---|---|
| 56Gastable | 31 | 25 | 55.995878 | Stable | p | 3+ | — |
| 57Gastable | 31 | 26 | 56.983457 | Stable | p | 1/2- | — |
| 58Gastable | 31 | 27 | 57.974729 | Stable | p | 2+ | — |
| 59Gastable | 31 | 28 | 58.963757 | Stable | p | 3/2- | — |
| 69Gastable | 31 | 38 | 68.925574 | Stable | stable (1%) | 3/2- | 6010.8000% |
| 71Gastable | 31 | 40 | 70.924703 | Stable | stable (1%) | 3/2- | 3989.2000% |
| 86Ga | 31 | 55 | 85.963757 | 49.0 ms | β⁻ (1%), β⁻n (0.69%), 2n (0.162%) | — | — |
| 87Ga | 31 | 56 | 86.969007 | 29.0 ms | β⁻ (1%), β⁻n (0.81%), 2n (0.102%) | 5/2- | — |
| 88Gastable | 31 | 57 | 87.975963 | Stable | β⁻, β⁻n | — | — |