Gallium

  • gallium, 31ga
    gallium crystals.jpg
    gallium
    pronunciationm/ (gal-ee-əm)
    appearancesilvery blue
    standard atomic weight ar, std(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
    blockp-block
    element category  post-transition metal
    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, +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
    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)
    main isotopes of gallium
    iso­tope abun­dance half-life (t1/2) decay mode pro­duct
    66ga syn 9.5 h β+ 66zn
    67ga syn 3.3 d ε 67zn
    68ga syn 1.2 h β+ 68zn
    69ga 60.11% stable
    70ga syn 21 min β 70ge
    ε 70zn
    71ga 39.89% stable
    72ga syn 14.1 h β 72ge
    73ga syn 4.9 h β 73ge
    category category: gallium
    | references

    gallium is a chemical element with the symbol ga and atomic number 31. elemental gallium is a soft, silvery blue metal at standard temperature and pressure; however in its liquid state it becomes silvery white. if too much force is applied, the gallium may fracture conchoidally. it is in group 13 of the periodic table, and thus has similarities to the other metals of the group, aluminium, indium, and thallium. gallium does not occur as a free element in nature, but as gallium(iii) compounds in trace amounts in zinc ores and in bauxite.[6] elemental gallium is a liquid at temperatures greater than 29.76 °c (85.57 °f), above room temperature, but below the normal human body temperature of 37 °c (99 °f). hence, the metal will melt in a person's hands.

    the melting point of gallium is used as a temperature reference point. gallium alloys are used in thermometers as a non-toxic and environmentally friendly alternative to mercury, and can withstand higher temperatures than mercury. an even lower melting point of −19 °c (−2 °f), well below the freezing point of water, is claimed for the alloy galinstan (62–⁠95% gallium, 5–⁠22% indium, and 0–⁠16% tin by weight), but that may be the freezing point with the effect of supercooling.

    since its discovery in 1875, gallium has been used to make alloys with low melting points. it is also used in semiconductors as a dopant in semiconductor substrates.

    gallium is predominantly used in electronics. gallium arsenide, the primary chemical compound of gallium in electronics, is used in microwave circuits, high-speed switching circuits, and infrared circuits. semiconducting gallium nitride and indium gallium nitride produce blue and violet light-emitting diodes (leds) and diode lasers. gallium is also used in the production of artificial gadolinium gallium garnet for jewelry. gallium is considered a technology-critical element.

    gallium has no known natural role in biology. gallium(iii) behaves in a similar manner to ferric salts in biological systems and has been used in some medical applications, including pharmaceuticals and radiopharmaceuticals.

  • physical properties
  • chemical properties
  • history
  • occurrence
  • production and availability
  • applications
  • precautions
  • see also
  • references
  • bibliography
  • external links

Gallium, 31Ga
Gallium crystals.jpg
Gallium
Pronunciationm/ (GAL-ee-əm)
Appearancesilvery blue
Standard atomic weight Ar, std(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
Blockp-block
Element category  Post-transition metal
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, +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
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)
Main isotopes of gallium
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct
66Ga syn 9.5 h β+ 66Zn
67Ga syn 3.3 d ε 67Zn
68Ga syn 1.2 h β+ 68Zn
69Ga 60.11% stable
70Ga syn 21 min β 70Ge
ε 70Zn
71Ga 39.89% stable
72Ga syn 14.1 h β 72Ge
73Ga syn 4.9 h β 73Ge
Category Category: Gallium
| references

Gallium is a chemical element with the symbol Ga and atomic number 31. Elemental gallium is a soft, silvery blue metal at standard temperature and pressure; however in its liquid state it becomes silvery white. If too much force is applied, the gallium may fracture conchoidally. It is in group 13 of the periodic table, and thus has similarities to the other metals of the group, aluminium, indium, and thallium. Gallium does not occur as a free element in nature, but as gallium(III) compounds in trace amounts in zinc ores and in bauxite.[6] Elemental gallium is a liquid at temperatures greater than 29.76 °C (85.57 °F), above room temperature, but below the normal human body temperature of 37 °C (99 °F). Hence, the metal will melt in a person's hands.

The melting point of gallium is used as a temperature reference point. Gallium alloys are used in thermometers as a non-toxic and environmentally friendly alternative to mercury, and can withstand higher temperatures than mercury. An even lower melting point of −19 °C (−2 °F), well below the freezing point of water, is claimed for the alloy galinstan (62–⁠95% gallium, 5–⁠22% indium, and 0–⁠16% tin by weight), but that may be the freezing point with the effect of supercooling.

Since its discovery in 1875, gallium has been used to make alloys with low melting points. It is also used in semiconductors as a dopant in semiconductor substrates.

Gallium is predominantly used in electronics. Gallium arsenide, the primary chemical compound of gallium in electronics, is used in microwave circuits, high-speed switching circuits, and infrared circuits. Semiconducting gallium nitride and indium gallium nitride produce blue and violet light-emitting diodes (LEDs) and diode lasers. Gallium is also used in the production of artificial gadolinium gallium garnet for jewelry. Gallium is considered a technology-critical element.

Gallium has no known natural role in biology. Gallium(III) behaves in a similar manner to ferric salts in biological systems and has been used in some medical applications, including pharmaceuticals and radiopharmaceuticals.