Properties of Metals and Non metals -2

1. Why do metals loose their lustre when exposed to air?
2. What do you understand by malleability?
3. Ductility of aluminium is used in several ways.Justify the statement by giving two examples.
4. Name the most ductile metal.
5. Metals have high tensile strength.Why?
6. What is conductivity?
7. Name one non metal which has high tensile strength.

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