Gold:
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Atomic number
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79
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Symbol
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Au
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Atomic weight
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196.9665
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discovery
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Known since prehistoric time
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Electrical configuration
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[Xe]6s'4f145d10
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Word origin
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Sanskrit, jwal: meaning gold also Latin aurum, shining drawn.
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Melting point
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1064.430C
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Boiling point
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27000C
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Specific gravity
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18.88 (200C)
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Electrical resistivity
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2.2*10-8 ohm-m
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Properties:
1. In mass, gold is a yellow coloured metal, although it may be black, ruby, or purple when finally divided.
2. It is one of the stable metals and it is very light and soft.
3. It is a malleable and ductile and can be easily beaten into translucent sheets as thin as 0.00001mm.
4. It is a good conductor of electricity and heat. It is not affected by exposure to air or to most reagents.
5. It is inert and good reflector to infrared radiation.
6. It is very soft and cannot be used in pure form. So, it is usually alloyed to improve its resistance to mechanical wear and to impact hardness.
7. It is highly corrosion resistant which makes it alloy very much useful as contact materials in electric field.
Uses:
1. Gold is used in coinage and is the standard for many monetary systems.
2. It is used for jewellery, dental work, plating and reflectors.
3. Chlorauric acid is used in photography for toning silver images.
4. Disodium aurothiomalate administered intramuscularly is a treatment for arthritis.ents
5. It is extensively used to make contacts on very sensitive devices where clean contact surface is essential. It is also used in inter connections within the integrated circuits.
Sources: Gold is generally found in veins among rocks and ores of other metal. It is also found in the form of dust in the beds of rivers. Gold is widely distributed and almost always associated with pyrite or quartz.