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Au - Gold

Gold

 Gold 
Au
Atomic Number: 79
Atomic Weight: 196.9665
Element Type: Transition Metal
Crystal Structure: Cubic Face Centered
Melting Point: 1064.18°C = 1947.524°F = 1337.33 K
Boiling Point: 2856.0°C = 5172.8°F = 3129.15 K
Critical Temp: °C = °F = K
Atomic Radius: 1.79 Å (Å = Angstrom = 10-10 m)
Covalent Radius: 1.34 Å
Electronegativity: 2.4

History

(Sanskrit Jval; Anglo-Saxon gold; L. aurum, gold) Known and highly valued from earliesttimes, gold is found in nature as the free metal and in tellurides; it is very widelydistributed and is almost always associated with quartz or pyrite.


Sources

It occurs in veins and alluvial deposits, and is often separated from rocks and otherminerals by mining and panning operations. About two thirds of the world's gold outputcomes from South Africa, and about two thirds of the total U.S. production comes fromSouth Dakota and Nevada. The metal is recovered from its ores by cyaniding, amalgamating,and smelting processes. Refining is also frequently done by electrolysis. Gold occurs insea water to the extent of 0.1 to 2 mg/ton, depending on the location where the sample istaken. As yet, no method has been found for recovering gold from sea water profitably.



Science Quote

'The true spirit of delight, the exaltation, the sense of being more than Man, which is the touchstone of the highest excellence, is to be found in mathematics as surely as in poetry.'

Bertrand Russell
(1872-1970)


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