Decaying of upper layer of metals due to the action of gases , moisture, acids etc. We can prevent it by electroplating , greasing, painting, alloying and lubrication
1 1 1
The Brainliest Answer!
When some metals are exposed to moisture, acids etc., they tarnish due to the formation of respective metal oxide on their surface.This process is called  corrosion.Corrosion can be prevented by painting the surface, oiling, greasing, galvanizing, chrome plating or making alloys.
1 5 1