Gallium

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Gallium,  31Ga
Gallium crystals.jpg
General properties
Appearance silver-white
Staundart atomic wecht (Ar, staundart) 69.723(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 Gold 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
Group group 13 (boron group)
Period period 4
Element category   post-transition metal
Block p-block
Electron confeeguration [Ar] 4s2 3d10 4p1
Electrons per shell
2, 8, 18, 3
Pheesical properties
Phase (at STP) solit
Meltin pynt 302.9146 K ​(29.7646 °C, ​85.5763 °F)
Bylin pynt 2477 K ​(2204 °C, ​3999 °F)
Density (near r.t.) 5.91 g/cm3
when liquid (at m.p.) 6.095 g/cm3
Heat o fusion 5.59 kJ/mol
Heat o vapourisation 254 kJ/mol
Molar heat capacity 25.86 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 3, 2, 1 amphoteric oxide
Electronegativity Pauling scale: 1.81
Ionisation energies
Atomic radius empirical: 135 pm
Covalent radius 122±3 pm
Van der Waals radius 187 pm
Color lines in a spectral range
Miscellanea
Creestal structur orthorhombic
Orthorhombic creestal structur for gallium
Speed o soond thin rod 2740 m/s (at 20 °C)
Thermal expansion 18 µm/(m·K) (at 25 °C)
Thermal conductivity 40.6 W/(m·K)
Electrical resistivity 270 n Ω·m (at 20 °C)
Magnetic orderin diamagnetic
Young's modulus 9.8 GPa
Poisson ratio 0.47
Mohs haurdness 1.5
Brinell haurdness 60 MPa
CAS Nummer 7440-55-3
History
Predeection Dmitri Mendeleev (1871)
Diskivery Lecoq de Boisbaudran (1875)
First isolation Lecoq 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 | in Wikidata

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.

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