Gallium

chemical element with symbol Ga and atomic number 31

Gallium (chemical symbol: Ga) is element 31 on the periodic table. It is a soft, gray metal that is rare on Earth. It can easily be melted just by holding it in your hand, as its melting point is very low 29.76 Celsius (85.58 Fahrenheit), however it also sticks to your hand a lot, unlike Mercury. Gallium is a semiconductor, and as the compound Gallium arsenide it is used in electronics and LEDs. Then, Gallium is also used in mirrors. Gallium can also be alloyed with Indium and Tin to create Galinstan. Gallium is similar to the elements Aluminium, Indium and Mercury.[7]

Gallium, 31Ga
Gallium
Pronunciation/ˈɡæliəm/ (GAL-ee-əm)
Appearancesilvery blue
Standard atomic weight Ar°(Ga)
69.723(1)[1]
Gallium in the periodic table
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 Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver 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 Gold Mercury (element) Thallium Lead 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 Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
Al

Ga

In
zincgalliumgermanium
Atomic number (Z)31
Groupgroup 13 (boron group)
Periodperiod 4
Block  p-block
Electron configuration[Ar] 3d10 4s2 4p1
Electrons per shell2, 8, 18, 3
Physical properties
Phase at STPsolid
Melting point302.9146 K ​(29.7646 °C, ​85.5763 °F)
Boiling point2673 K ​(2400 °C, ​4352 °F)[2]
Density (near r.t.)5.91 g/cm3
when liquid (at m.p.)6.095 g/cm3
Heat of fusion5.59 kJ/mol
Heat of vaporization256 kJ/mol[2]
Molar heat capacity25.86 J/(mol·K)
Vapor pressure
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,[3] −2, −1, 0, +1, +2, +3[4] (an amphoteric oxide)
ElectronegativityPauling scale: 1.81
Ionization energies
  • 1st: 578.8 kJ/mol
  • 2nd: 1979.3 kJ/mol
  • 3rd: 2963 kJ/mol
  • (more)
Atomic radiusempirical: 135 pm
Covalent radius122±3 pm
Van der Waals radius187 pm
Color lines in a spectral range
Spectral lines of gallium
Other properties
Natural occurrenceprimordial
Crystal structureorthorhombic
Orthorhombic crystal structure for gallium
Speed of sound thin rod2740 m/s (at 20 °C)
Thermal expansion18 µm/(m⋅K) (at 25 °C)
Thermal conductivity40.6 W/(m⋅K)
Electrical resistivity270 nΩ⋅m (at 20 °C)
Magnetic orderingdiamagnetic
Molar magnetic susceptibility−21.6×10−6 cm3/mol (at 290 K)[5]
Young's modulus9.8 GPa
Poisson ratio0.47
Mohs hardness1.5
Brinell hardness56.8–68.7 MPa
CAS Number7440-55-3
History
Namingafter Gallia (Latin for: France), homeland of the discoverer
PredictionDmitri Mendeleev (1871)
Discovery and first isolationLecoq de Boisbaudran (1875)
Isotopes of gallium
Main isotopes[6] Decay
abun­dance half-life (t1/2) mode pro­duct
66Ga synth 9.5 h β+ 66Zn
67Ga synth 3.3 d ε 67Zn
68Ga synth 1.2 h β+ 68Zn
69Ga 60.1% stable
70Ga synth 21 min β 70Ge
ε 70Zn
71Ga 39.9% stable
72Ga synth 14.1 h β 72Ge
73Ga synth 4.9 h β 73Ge
 Category: Gallium
| references
Crystals of gallium joined together

Gallium's existence was predicted by Dmitri Mendeleev in 1871. Four years later, it was discovered by Paul-Émile Lecoq de Boisbaudran.[7]

Reference

change
  1. "Standard Atomic Weights: Gallium". CIAAW. 1987.
  2. 2.0 2.1 Zhang Y; Evans JRG; Zhang S (2011). "Corrected Values for Boiling Points and Enthalpies of Vaporization of Elements in Handbooks". J. Chem. Eng. Data. 56 (2): 328–337. doi:10.1021/je1011086.
  3. 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.
  4. Hofmann, Patrick (1997). Colture. Ein Programm zur interaktiven Visualisierung von Festkörperstrukturen sowie Synthese, Struktur und Eigenschaften von binären und ternären Alkali- und Erdalkalimetallgalliden (PDF) (Thesis) (in German). PhD Thesis, ETH Zurich. p. 72. doi:10.3929/ethz-a-001859893. hdl:20.500.11850/143357. ISBN 978-3728125972.
  5. Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.
  6. Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  7. 7.0 7.1 "Gallium | Uses, Properties, & Facts | Britannica". www.britannica.com. 2024-04-23. Retrieved 2024-05-18.