Gallium

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Gallium
31Ga
Al

Ga

In
zincgalliumgermanium
Appearance
silver-white
General properties
Name, seembol, nummer gallium, Ga, 31
Pronunciation /ˈɡæliəm/ GAL-ee-əm
Element category poor metal
Group, period, block 13, 4, p
Staundart atomic wicht 69.723(1)
Electron confeeguration [Ar] 4s2 3d10 4p1
2, 8, 18, 3
Electron shells of gallium (2, 8, 18, 3)
History
Namin after Gallia (Laitin for: Fraunce), homeland o the discoverer
Prediction Dmitri Mendeleev (1871)
Discovery Lecoq de Boisbaudran (1875)
First isolation Lecoq de Boisbaudran (1875)
Physical properties
Phase solid
Density (near r.t.) 5.91 g·cm−3
Liquid density at m.p. 6.095 g·cm−3
Meltin pynt 302.9146 K, 29.7646 °C, 85.5763 °F
Boilin pynt 2477 K, 2204 °C, 3999 °F
Heat o fusion 5.59 kJ·mol−1
Heat o vaporization 254 kJ·mol−1
Molar heat capacity 25.86 J·mol−1·K−1
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 3, 2, 1
(amphoteric oxide)
Electronegativity 1.81 (Pauling scale)
Ionization energies
(more)
1st: 578.8 kJ·mol−1
2nt: 1979.3 kJ·mol−1
3rd: 2963 kJ·mol−1
Atomic radius 135 pm
Covalent radius 122±3 pm
Van der Waals radius 187 pm
Miscellanea
Crystal structure orthorhombic
Gallium has a orthorhombic crystal structure
Magnetic orderin diamagnetic
Electrical resistivity (20 °C) 270 nΩ·m
Thermal conductivity 40.6 W·m−1·K−1
Thermal expansion (25 °C) 18 µm·m−1·K−1
Speed of sound (thin rod) (20 °C) 2740 m·s−1
Young's modulus 9.8 GPa
Poisson ratio 0.47
Mohs hairdness 1.5
Brinell hairdness 60 MPa
CAS registry nummer 7440-55-3
Most stable isotopes
Main article: Isotopes o gallium
iso NA hauf-life DM DE (MeV) DP
69Ga 60.11% 69Ga is stable wi 38 neutrons
71Ga 39.89% 71Ga is stable wi 40 neutrons
· r

Gallium is a chemical element wi seembol Ga an atomic nummer 31. Elemental gallium daes nae occur in free furm in naitur, but as the gallium(III) compoonds that are in trace amoonts in zinc ores an in bauxite. Gallium is a saft sillery metal, an elemental gallium is a brittle solid at law temperaturs. If it is held in the human haund long enough, gallium will melt, syne it melts at the temperatur o about 29.76 °C (85.57 °F) (slichtly above 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), well ablo the freezin pynt o watter. Beginnin wi its discovery in 1875 through the era o semiconductors, gallium wis uised primarily as an agent tae mak alloys that melt at law temperaturs. Then, gallium acame uiseful in semiconductors, includin as a dopant.

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