The natural process that causes the transformation of pure metals to undesirable substances when they react with substances like water or air is called corrosion.
Following are the advantages of corrosion:
i) Layer of protection: A layer of oxide is formed on the surface that is corrosion protects the inner metal from corrosion
ii) Sacrificial anodes such as zinc is used as a preventive measure to stop corrosion of other metals
iii) Galvanic corrosion: This kind of corrosion occurs when two different types of metals are in electrical contact in an electrolyte where the more active metal tends to corrode.
Following are the disadvantages of corrosion:
i)Lose of metal from the surface
ii) The physical appearance of a metal object changes
iii)The chemical properties of metal varies
iv)Lose of the efficiency of metallic machines
v) The life span of metallic objects decreases