Answers

2014-08-21T19:55:49+05:30
DUE TO EXPOSURE TO AIR, SOME METALS LOOSE THEIR LUSTER. EX : IRON
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2014-08-21T19:59:49+05:30
Metals react with the atmosphere oxygen and the oxygen is bonded to them.after a layer of oxide forms over the surface, the metals lose their lustre.this does not happen in case of metals like Platinum and gold as it is difficult to oxidise them.

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