question_answer

  Which two metals do not corrode easily? Give an example in each case to support that (i) corrosion of some metals is an advantage. (ii) corrosion of some metals is a serious problem.

Answer:

                  Gold and platinum. (i) A thin impervious layer of aluminium oxide forms a protective layer which protects the aluminium metals underneath from further damage. (ii) Corrosion of iron is a serious problem. Every year enormous amount of money is spent to replace damaged iron and steel structures.