Sun September 08, 2013 By:

why do some metals lose their lusture when exposed to air

Expert Reply
Vaibhav Chavan
Tue September 10, 2013
Metals lose their brightness when they are exposed to air and moisture. Oxygen  of the atmosphere  facilitates the oxidation reaction of metals forming metallic oxides on its surface and hence metals lose their brightness in long run.The eating up of metals by the action of air,moisture or a chemical(such as an acid) on their surface is called corrosion.
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