Element: Gallium
General data
| Element name | Gallium |
|---|---|
| Chemical symbol | Ga |
| Atomic number Z | 31 |
| Year discovered | 1875 |
| Standard state (25°C) | Solid |
| Category | Post-transition metal |
| Block | p |
| Atomic mass | 69.723 |
| CPK color | #C28F8F |
Physical properties
| Melting point | 302.91 K (29.76 °C) |
|---|---|
| Boiling point | 2477 K (2204 °C) |
| Density | 5.91 g/cm³ |
Energy properties
| First ionization energy | 5.999 eV |
|---|---|
| Electron affinity | 0.3 eV |
Atomic structure
| Protons | 31 (Atomic number) |
|---|---|
| Neutrons (Ga-69, most abundant isotope) | 38 |
| Electrons | 31 |
| Electron configuration | [Ar] 4s² 3d¹⁰ 4p¹ |
| Oxidation states | +3 |
| Electronegativity (Pauling) | 1.81 |
| Atomic radius (van der Waals) | 187 pm |
Ionization energies - NIST ASD (31 states)
| State | Charge | Ioniz. energy (eV) | Type |
|---|---|---|---|
| Ga I | 0+ | 5.999302 ± 0.0000012 | measured |
| Ga II | 1+ | 20.51514 ± 0.00012 | measured |
| Ga III | 2+ | 30.72576 ± 0.00025 | measured |
| Ga IV | 3+ | 63.241 ± 0.009 | measured |
| Ga V | 4+ | 86.01 ± 0.12 | semi-empirical |
| Ga VI | 5+ | 112.7 ± 1.1 | calculated |
| Ga VII | 6+ | 140.8 ± 1.4 | calculated |
| Ga VIII | 7+ | 169.9 ± 1.7 | calculated |
| Ga IX | 8+ | 211 ± 2.2 | calculated |
| Ga X | 9+ | 244 ± 2.5 | calculated |
| Ga XI | 10+ | 280 ± 2.4 | calculated |
| Ga XII | 11+ | 319 ± 2.5 | calculated |
| Ga XIII | 12+ | 356 ± 3 | calculated |
| Ga XIV | 13+ | 471.2 ± 1.4 | semi-empirical |
| Ga XV | 14+ | 508.8 ± 0.4 | semi-empirical |
| Ga XVI | 15+ | 548.3 ± 0.7 | semi-empirical |
| Ga XVII | 16+ | 599.8 ± 1.4 | semi-empirical |
| Ga XVIII | 17+ | 640 ± 1.5 | semi-empirical |
| Ga XIX | 18+ | 677 ± 3 | semi-empirical |
| Ga XX | 19+ | 765.7 ± 0.9 | semi-empirical |
| Ga XXI | 20+ | 807.308 ± 0.025 | semi-empirical |
| Ga XXII | 21+ | 2010 ± 1.1 | semi-empirical |
| Ga XXIII | 22+ | 2129 ± 4 | semi-empirical |
| Ga XXIV | 23+ | 2258 ± 5 | semi-empirical |
| Ga XXV | 24+ | 2391 ± 18 | semi-empirical |
| Ga XXVI | 25+ | 2543.9 ± 2 | semi-empirical |
| Ga XXVII | 26+ | 2683 ± 1.4 | semi-empirical |
| Ga XXVIII | 27+ | 2868 ± 3 | semi-empirical |
| Ga XXIX | 28+ | 2984.426 ± 0.007 | calculated |
| Ga XXX | 29+ | 12696.5581 ± 0.0016 | calculated |
| Ga XXXI | 30+ | 13239.5029 ± 0.0007 | calculated |
Value type as given by NIST ASD: measured - from evaluated experimental data; calculated - from ab initio calculations (mostly highly ionised atoms that have not been measured; for the simplest ones, e.g. H I, the calculation is more accurate than measurement); semi-empirical - from interpolation, extrapolation or another semi-empirical method.
Photos
Isotopes (29)
| A | N | Half-life | Decay |
|---|---|---|---|
| Ga-59 | 28 | < 43 ns | p |
| Ga-60 | 29 | 69.4 ms | EC/β⁺ |
| Ga-61 | 30 | 166 ms | EC/β⁺ |
| Ga-62 | 31 | 116.123 ms | EC/β⁺ |
| Ga-63 | 32 | 32.1 s | EC/β⁺ |
| Ga-64 | 33 | 2.627 min | EC/β⁺ |
| Ga-65 | 34 | 15.13 min | EC/β⁺ |
| Ga-66 | 35 | 9.304 h | EC/β⁺ |
| Ga-67 | 36 | 3.2615 d | EC |
| Ga-68 | 37 | 67.843 min | EC/β⁺ |
| Ga-69 | 38 | stable | - |
| Ga-70 | 39 | 21.14 min | β⁻ |
| Ga-71 | 40 | stable | - |
| Ga-72 | 41 | 14.03 h | β⁻ |
| Ga-73 | 42 | 4.87 h | β⁻ |
| Ga-74 | 43 | 8.10 min | β⁻ |
| Ga-75 | 44 | 126 s | β⁻ |
| Ga-76 | 45 | 31.0 s | β⁻ |
| Ga-77 | 46 | 13.2 s | β⁻ |
| Ga-78 | 47 | 5.09 s | β⁻ |
| Ga-79 | 48 | 2.848 s | β⁻ |
| Ga-80 | 49 | 1.9 s | β⁻ |
| Ga-81 | 50 | 1.217 s | β⁻ |
| Ga-82 | 51 | 600 ms | β⁻ |
| Ga-83 | 52 | 310 ms | β⁻ |
| Ga-84 | 53 | 97.6 ms | β⁻ |
| Ga-85 | 54 | 95.1 ms | β⁻ |
| Ga-86 | 55 | 49 ms | β⁻ |
| Ga-87 | 56 | 29 ms | β⁻ |
Data sources
- PubChem Periodic Table API - Retrieved on 29 June 2026 - licence: CC0
- IUPAC CIAAW - Abridged Standard Atomic Weights 2024 - Table version: 2024 - licence: Public domain
- NNDC Wallet Cards 2023 - Data as of 15 October 2024 - licence: Public domain
- NIST Atomic Spectra Database (ASD) - Retrieved on 29 June 2026 - licence: © U.S. Secretary of Commerce
- Images of Elements - Retrieved on 29 June 2026 - licence: CC BY 3.0