tin

Name tin
Symbol Sn
Atomic Weight 118.710
Atomic Number 50
CAS ID 7440-31-5
Group Number 14
Group Name (none)
Period Number 5
Origin of Name Anglo-Saxon, tin; Latin stannum.
Year Discovered Prehistoric
Discovery Credits Known to ancient civilizations.
Class Metallic
Color Silvery Lustrous Gray
Standard State Solid at 77 F & 298 K
Description Soft, pliable, silvery-white metal. Unreactive to oxygen (protected by an oxide film) and water but dissolves in acids and bases. Used in solders, alloys, tinplate, polymer additives and anti-fouling paints.

Diagnostic tests: 
Tin is usually detected by the formation of metallic tin globules by reduction of the mineral on charcoal with the blowpipe.

Mix 1 part powdered mineral with 1 part charcoal and 2 parts Na2CO3 with enough water to make a paste. Heat on charcoal block with a reducing flame and the tin should be easily reduced and collect into globules of metallic tin which are bright in the reducing flame and dull when cooled because of the formation of an oxide coat. 
The globules are distinguished from lead or bismuth by the lack of a yellow coating of the oxide on charcoal and from silver by the dull presence of a coating of oxide upon cooling.

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