Gallium is a chemical element wi seembol Ga an atomic nummer 31. Elemental gallium disnae occur in free furm in naitur, but as the gallium(III) compoonds that is in trace amoonts in zinc ores an in bauxite. Gallium is a saft sillery metal, an elemental gallium is a brickle solit at law temperaturs. Gif it is held in the human haund lang eneuch, gallium will melt, syne it melts at the temperatur o aboot 29.76 °C (85.57 °F) (slichtly abuin ruim temperatur). The meltin pynt o gallium is uised as a temperatur reference pynt. The alloy galinstan (68.5% gallium, 21.5% indium, an 10% tin) haes the even lawer meltin pynt o −19 °C (−2 °F), weel ablo the freezin pynt o watter. Beginnin wi its discovery in 1875 throu the era o semiconductors, gallium wis uised primarily as an agent tae mak alloys that melt at law temperaturs. Then, gallium became uiseful in semiconductors, includin as a dopant.

Gallium, 31Ga
Template:Infobox element/symbol-to-top-image/alt
Gallium
Pronunciation/ˈɡæliəm/ (GAL-ee-əm)
Appearancesilver-white
Standard atomic weight Ar, std(Ga)69.723(1)[1]
Gallium in the periodic cairt
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gowd Mercur (element) Thallium Leid (element) Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium
Al

Ga

In
zincgalliumgermanium
Atomic nummer (Z)31
Groupgroup 13 (boron group)
Periodperiod 4
Blockp-block
Element category  Post-transeetion metal
Electron confeeguration[Ar] 3d10 4s2 4p1
Electrons per shell2, 8, 18, 3
Pheesical properties
Phase at STPsolit
Meltin pynt302.9146 K ​(29.7646 °C, ​85.5763 °F)
Bylin pynt2477 K ​(2204 °C, ​3999 °F)
Density (near r.t.)5.91 g/cm3
when liquid (at m.p.)6.095 g/cm3
Heat o fusion5.59 kJ/mol
Heat o vapourisation254 kJ/mol
Molar heat capacity25.86 J/(mol·K)
Vapour pressur
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1310 1448 1620 1838 2125 2518
Atomic properties
Oxidation states−5, −4, −3,[2] −2, −1, +1, +2, +3[3] (an amphoteric oxide)
ElectronegativityPauling scale: 1.81
Ionisation energies
Atomic radiusempirical: 135 pm
Covalent radius122±3 pm
Van der Waals radius187 pm
Colour lines in a spectral range
Colour lines in a spectral range
Spectral lines o gallium
Ither properties
Naitural occurrenceprimordial
Creestal structurorthorhombic
Orthorhombic creestal structur for gallium
Speed o soond thin rod2740 m/s (at 20 °C)
Thermal expansion18 µm/(m·K) (at 25 °C)
Thermal conductivity40.6 W/(m·K)
Electrical resistivity270 n Ω·m (at 20 °C)
Magnetic orderindiamagnetic
Young's modulus9.8 GPa
Poisson ratio0.47
Mohs haurdness1.5
Brinell haurdness60 MPa
CAS Nummer7440-55-3
History
PredictionDmitri Mendeleev (1871)
DiskiveryLecoq de Boisbaudran (1875)
First isolationLecoq de Boisbaudran (1875)
Main isotopes o gallium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
69Ga 60.11% stable
71Ga 39.89% stable
| references

References

eedit
  1. Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
  2. Ga(−3) has been observed in LaGa, see Dürr, Ines; Bauer, Britta; Röhr, Caroline (2011). "Lanthan-Triel/Tetrel-ide La(Al,Ga)x(Si,Ge)1-x. Experimentelle und theoretische Studien zur Stabilität intermetallischer 1:1-Phasen" (PDF). Z. Naturforsch. (in German). 66b: 1107–1121.
  3. Hofmann, Patrick (1997). Colture. Ein Programm zur interaktiven Visualisierung von Festkörperstrukturen sowie Synthese, Struktur und Eigenschaften von binären und ternären Alkali- und Erdalkalimetallgalliden (PDF) (in German). PhD Thesis, ETH Zurich. p. 72. doi:10.3929/ethz-a-001859893. ISBN 978-3728125972.