| Atomic Mass | 69.723 |
|---|---|
| Electron Configuration | [Ar]4s23d104p1 |
| Oxidation States | +3 |
| Year Discovered | 1875 |
| Atomic Mass | 69.723 |
|---|---|
| Electron Configuration | [Ar]4s23d104p1 |
| Oxidation States | +3 |
| Year Discovered | 1875 |
| Element Name | Gallium |
|---|---|
| Element Symbol | Ga |
| InChI | InChI=1S/Ga |
| InChIKey | GYHNNYVSQQEPJS-UHFFFAOYSA-N |
| Atomic Weight |
69.723(1) 69.723 69.72 69.723(1) |
|---|---|
| Electron Configuration |
[Ar]4s23d104p1 |
| Atomic Radius |
Van der Waals Atomic Radius : 187 pm (Van der Waals) Empirical Atomic Radius : 130pm (Empirical) Covalent Atomic Radius : 122(3) pm (Covalent) |
| Oxidation States |
+3 3, 2, 1, -1, -2, -4, -5 (an amphoteric oxide) |
| Ground Level |
2P°1/2 |
| Ionization Energy |
5.999 eV 5.9993020 ± 0.0000012 eV |
| Electronegativity |
Pauling Scale Electronegativity : 1.81(Pauling Scale) Allen Scale Electronegativity : 1.756(Allen Scale) |
| Electron Affinity |
0.3eV 0.37eV |
| Atomic Spectra |
Lines Holdings Levels Holdings |
| Physical Description |
Solid |
| Element Classification |
Metal |
| Element Period Number |
4 |
| Element Group Number |
13 |
| Density |
5.91 grams per cubic centimeter |
| Melting Point |
302.91 K (29.76°C or 85.57°F) 29.76°C |
| Boiling Point |
2477 K (2204°C or 3999°F) 2400°C |
| Estimated Crustal Abundance |
1.9×101 milligrams per kilogram |
| Estimated Oceanic Abundance |
3×10-5 milligrams per liter |
The name derives from the Latin gallia for France. It was discovered in zinc blende by the French chemist Paul-Emile Lecoq de Boisbaudran in 1875. It was first isolated in 1878 by Lecoq de Boisbaudran and the French chemist Émile-Clément Jungflesch.
First proposed to exist by Dmitri Mendeleyev in 1871 based on gaps in his newly created Periodic Table of Elements, gallium was discovered spectroscopically by the French chemist Paul-Émile Lecoq de Boisbaudran in 1875. Later that same year, Lecoq was able to obtain pure gallium through the electrolysis of a solution of gallium hydroxide (Ga(OH)3) in potassium hydroxide (KOH). Trace amounts of gallium are found in diaspore, sphalerite, germanite and bauxite as well as in the byproducts of burning coal.
From the Latin word Gallia, France; also from Latin, gallus, a translation of "Lecoq," a cock. Predicted and described by Mendeleev as ekaaluminum, and discovered spectroscopically by Lecoq de Boisbaudran in 1875, who in the same year obtained the free metal by electrolysis of a solution of the hydroxide in KOH.
| Year | Atomic Weight (uncertainty) [u] | Reference |
|---|---|---|
| 1987 | 69.723(1) | https://doi.org/10.1351/pac198860060841 |
| 1983 | 69.723(4) | https://doi.org/10.1351/pac198456060653 |
| 1969 | 69.72(1) | https://doi.org/10.1351/pac197021010091 |
| 1925 | 69.72 | https://doi.org/10.1039/CT9252700913 |
| 1920 | 70.1 | https://doi.org/10.1021/ja02233a600 |
| 1909 | 69.9 | https://doi.org/10.1021/ja01931a001 |
| 1902 | 70.0 | https://doi.org/10.1007/BF01370337 |
| Year | Isotope | Abundance (uncertainty) | Reference |
|---|---|---|---|
| 2013 | 69Ga | 0.601 08(50) | https://doi.org/10.1515/pac-2015-0503 |
| 2013 | 71Ga | 0.398 92(50) | https://doi.org/10.1515/pac-2015-0503 |
| 1989 | 69Ga | 0.601 08(9) | https://doi.org/10.1351/pac199163070991 |
| 1989 | 71Ga | 0.398 92(9) | https://doi.org/10.1351/pac199163070991 |
| 1981 | 69Ga | 0.601(2) | https://doi.org/10.1351/pac198355071119 |
| 1981 | 71Ga | 0.399(2) | https://doi.org/10.1351/pac198355071119 |
| 1975 | 69Ga | 0.6 | https://doi.org/10.1351/pac197647010075 |
| 1975 | 71Ga | 0.4 | https://doi.org/10.1351/pac197647010075 |
It is one of four metals mercury, cesium, and rubidium which can be liquid near room temperature and, thus, can be used in high-temperature thermometers. It has one of the longest liquid ranges of any metal and has a low vapor pressure even at high temperatures.
There is a strong tendency for gallium to supercool below its freezing point. Therefore, seeding may be necessary to initiate solidification.
Ultra-pure gallium has a beautiful, silvery appearance, and the solid metal exhibits a conchoidal fracture similar to glass. The metal expands 3.1 percent on solidifying; therefore, it should not be stored in glass or metal containers, because they may break as the metal solidifies.
High-purity gallium is attacked only slowly by mineral acids.
Gallium melts near room temperature and has one of the largest liquid ranges of any metal, so it has found use in high temperature thermometers. Gallium easily forms alloys with most metals and has been used to create low melting alloys. Gallium is used as a doping material for semiconductors and has been used to produce solid-state items like transistors and light emitting diodes. Gallium arsenide (GaAs) can produce laser light directly from electricity. Large amounts of gallium trichloride (GaCl3) have been gathered to build the Gallium Neutrino Observatory, an observatory located in Italy built to study particles called neutrinos which are produced inside the sun during the process of nuclear fusion.
Gallium wets glass or porcelain and forms a brilliant mirror when it is painted on glass. It is widely used in doping semiconductors and producing solid-state devices such as transistors.
Magnesium gallate containing divalent impurities, such as Mn+2, is finding use in commercial ultraviolet-activated powder phosphors. Gallium arsenide is capable of converting electricity directly into coherent light. Gallium readily alloys with most metals, and has been used as a component in low-melting alloys.
Gallium is often found as a trace element in diaspore, sphalerite, germanite, bauxite, and coal. Some flue dusts from burning coal have been shown to contain as much 1.5 percent gallium.
See more information at the Gallium compound page.
| CID | Name | Formula | SMILES | Molecular Weight |
|---|---|---|---|---|
| 5360835 | gallium | Ga | [Ga] | 69.723 |
| 105145 | gallium(3+) | Ga+3 | [Ga+3] | 69.723 |
| 5464084 | gallium-67 | Ga | [67Ga] | 66.92820 |
| 6337047 | gallium-69 | Ga | [69Ga] | 68.92557 |
| 5488452 | gallium-68 | Ga | [68Ga] | 67.92798 |
| 6336609 | gallium-72 | Ga | [72Ga] | 71.926367 |
| 6337616 | gallium-66 | Ga | [66Ga] | 65.93159 |
| 44151867 | gallium-71 | Ga | [71Ga] | 70.924703 |
| 6337546 | gallium-70 | Ga | [70Ga] | 69.92602 |
| 6337567 | gallium-73 | Ga | [73Ga] | 72.92517 |
| 6337602 | gallium-65 | Ga | [65Ga] | 64.932734 |
| 11240419 | gallium-67(3+) | Ga+3 | [67Ga+3] | 66.92820 |
| 11457651 | gallium-68(3+) | Ga+3 | [68Ga+3] | 67.92798 |
| 11147669 | gallium-66(3+) | Ga+3 | [66Ga+3] | 65.93159 |
| 11665394 | gallium-64 | Ga | [64Ga] | 63.93684 |
| 25008869 | gallium-62 | Ga | [62Ga] | 61.944190 |
Its toxicity appears to be of a low order, but should be handled with care until more data is available.
| Stable Isotope Count | 2 |
|---|
68Ga (with a half-life of 68 min) is a radioactive isotope that emits positrons, which are used to produce high-resolution imaging with positron emission tomography (PET). Unlike 18F, which is most commonly used, 68Ga is more easily produced using a cost-effective generator with the parent radionuclide 68Ge (with a half-life of 271 days) (Fig. IUPAC.31.1). Once produced, 68Ga easily couples to biomolecules (most commonly peptides) that target G-protein coupled receptors, which are over-expressed on human tumor cells. The labeled protein acts as a radioactive tracer for cancer diagnostics. PET images are often coupled with CT images to get a more complete picture of the body [256], [257], [258], [259], [260], [261], [262]. Radiopharmaceutical 67Ga (with a half-life of 78 h) is a gamma-emitting isotope used in scintigraphy for medical imaging [263], [264], [265].
| Isotope | Atomic Mass (uncertainty) [u] | Abundance (uncertainty) |
|---|---|---|
| 69Ga | 68.925 573(8) | 0.601 08(50) |
| 71Ga | 70.924 702(6) | 0.398 92(50) |
| Isotope | Atomic Mass (uncertainty) [u] | Abundance (uncertainty) |
|---|---|---|
| 69Ga | 68.9255735(13) | 0.60108(9) |
| 71Ga | 70.92470258(87) | 0.39892(9) |
| Nuclide | Atomic Mass and Uncertainty [u] | Half Life and Uncertainty | Discovery Year | Decay Modes, Intensities and Uncertainties [%] |
|---|---|---|---|---|
| 56Ga | 55.995878 ± 0.000537 [Estimated] | Not-specified | p ? | |
| 57Ga | 56.983457 ± 0.000429 [Estimated] | Not-specified | p ? | |
| 58Ga | 57.974729 ± 0.000322 [Estimated] | Not-specified | p ? | |
| 58Gam | 57.974729 ± 0.000322 [Estimated] | Not-specified | p ? | |
| 59Ga | 58.963757 ± 0.000183 [Estimated] | Not-specified <43ns | p ? | |
| 60Ga | 59.957498 ± 0.000215 [Estimated] | 72.4 ms ± 1.7 | 1995 | β+=100%; β+p=1.6±0.7%; β+α<0.023±2% |
| 61Ga | 60.949398861 ± 0.000040787 | 165.9 ms ± 2.5 | 1987 | β+=100%; β+p<0.25% |
| 61Gam | 60.949398861 ± 0.000040787 | Not-specified | ||
| 62Ga | 61.944189639 ± 0.000000684 | 116.122 ms ± 0.021 | 1978 | β+=100% |
| 63Ga | 62.939294194 ± 0.0000014 | 32.4 s ± 0.5 | 1965 | β+=100% |
| 64Ga | 63.936840366 ± 0.000001533 | 2.627 m ± 0.012 | 1953 | β+=100% |
| 64Gam | 63.936840366 ± 0.000001533 | 21.9 us ± 0.7 | 1999 | IT=100% |
| 65Ga | 64.932734424 ± 0.000000849 | 15.133 m ± 0.028 | 1938 | β+=100% |
| 66Ga | 65.931589766 ± 0.000001172 | 9.304 h ± 0.008 | 1937 | β+=100% |
| 67Ga | 66.928202276 ± 0.000001262 | 3.2617 d ± 0.0004 | 1938 | ε=100% |
| 68Ga | 67.927980161 ± 0.000001535 | 67.842 m ± 0.016 | 1937 | β+=100% |
| 69Ga | 68.925573528 ± 0.000001285 | Stable | 1923 | IS=60.108±5% |
| 70Ga | 69.926021914 ± 0.000001289 | 21.14 m ± 0.05 | 1937 | β-=99.59±0.5%; ε=0.41±0.5% |
| 71Ga | 70.924702554 ± 0.00000087 | Stable | 1923 | IS=39.892±5% |
| 72Ga | 71.926367452 ± 0.000000878 | 14.025 h ± 0.010 | 1939 | β-=100% |
| 72Gam | 71.926367452 ± 0.000000878 | 39.68 ms ± 0.13 | 1968 | IT=100% |
| 73Ga | 72.925174680 ± 0.0000018 | 4.86 h ± 0.03 | 1949 | β-=100% |
| 73Gam | 72.925174680 ± 0.0000018 | <200 ms | 1949 | β- ?; IT ? |
| 74Ga | 73.926945725 ± 0.000003214 | 8.12 m ± 0.12 | 1956 | β-=100% |
| 74Gam | 73.926945725 ± 0.000003214 | 9.5 s ± 1.0 | 1974 | IT=75±2.5%; β- ? |
| 75Ga | 74.926504484 ± 0.00000072 | 126 s ± 2 | 1960 | β-=100% |
| 76Ga | 75.928827624 ± 0.0000021 | 30.6 s ± 0.6 | 1961 | β-=100% |
| 77Ga | 76.929154299 ± 0.0000026 | 13.2 s ± 0.2 | 1968 | β-=100[gs=12,m=88] |
| 78Ga | 77.931610854 ± 0.000001127 | 5.09 s ± 0.05 | 1972 | β-=100% |
| 78Gam | 77.931610854 ± 0.000001127 | 110 ns ± 3 | 2010 | IT=100% |
| 79Ga | 78.932851582 ± 0.000001296 | 2.848 s ± 0.003 | 1974 | β-=100%; β-n=0.089±1.9% |
| 80Ga | 79.936420773 ± 0.000003103 | 1.9 s ± 0.1 | 1974 | β-=100%; β-n=0.86±0.7% |
| 80Gam | 79.936420773 ± 0.000003103 | 1.3 s ± 0.2 | 2011 | β-≈100%; β-n ?; IT ? |
| 81Ga | 80.938133841 ± 0.000003503 | 1.217 s ± 0.005 | 1976 | β-=100%; β-n=12.5±0.5% |
| 82Ga | 81.943176531 ± 0.000002604 | 600 ms ± 2 | 1976 | β-=100%; β-n=21.2±1%; β-2n ? |
| 82Gam | 81.943176531 ± 0.000002604 | 93.5 ns ± 6.7 | 2009 | IT=100% |
| 83Ga | 82.947120300 ± 0.000002804 | 310.0 ms ± 0.7 | 1976 | β-=100%; β-n=85±0.4%; β-2n ? |
| 84Ga | 83.952663000 ± 0.000032 | 97.6 ms ± 1.2 | 1991 | β-=100%; β-n=43±0.4%; β-2n=1.6±0.2% |
| 84Gam | 83.952663000 ± 0.000032 | <85 ms | β- ?; IT ? | |
| 85Ga | 84.957333000 ± 0.00004 | 95.3 ms ± 1.0 | 1997 | β-=100%; β-n=77±0.4%; β-2n=1.3±0.2% |
| 86Ga | 85.963757 ± 0.000429 [Estimated] | 49 ms ± 2 | 1997 | β-=100%; β-n=69±0.6%; β-2n=16.2±1.1% |
| 87Ga | 86.969007 ± 0.000537 [Estimated] | 29 ms ± 4 | 2010 | β-=100%; β-n=81±1.2%; β-2n=10.2±0.28% |
| 88Ga | 87.975963 ± 0.000537 [Estimated] | Not-specified | β- ?; β-n ? |
