10th Class Science Metals and Non-metals Question Bank 10th CBSE Science Metals and Non-metals

  • question_answer   State the reason why? (a) Metals replace hydrogen from acids whereas non-metals do not. (b) Calcium does not occur free in nature. (c) Zinc is used in the galvanisation of iron and not the copper.

    Answer:

                      (a) The ionisation energy of metals is higher than hydrogen, so they can replace hydrogen from metal whereas ionisation energy of non-metal is lower than that of hydrogen hence they cannot displace hydrogen from acids. (1) (b) Calcium is very reactive and combine with oxygen or water vapour present in air to form compounds. Hence these metals are not found in the free state in nature.                                                   (1) (c) Zinc is used in the galvanisation of iron because zinc being more reactive metal than iron will get oxidised first as it is coated over the surface of iron. Thus, iron is prevented from rusting. Copper is less reactive than iron hence it will not react with iron and does not form any oxide layer on it.                                               (1)


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