question_answer 61)

  Cement, the important building material is a mixture of oxides of several elements. Besides calcium, iron and sulphur, oxides of elements of which of the group(s) is (are) present in the mixture? (a) group 2                          (b) group 2, 13, 14            (c) group 2 and 13            (d) group 2 and 14

Answer:

  (b) Cement consists oxides of calcium (group 2), aluminium (group 13) and silicon (group 14). Cement is a heavy powder containing calcium aluminates and silicates.