question_answer 27)

  Which of the following are physical changes? (i) Melting of iron metal (ii) Rusting of iron           (iii) Bending of an iron rod (iv) Drawing a wire of iron metal (a) (i), (ii) and (iii)             (b) (i), (ii) and (iv)             (c) (i), (iii) and (iv)            (d) (ii), (iii) and (iv)

Answer:

  (c) Options (i) Melting of iron metal, (iii) Bending of an iron rod and (iv) Drawing a wire of iron metal are physical changes, because in three processes, iron changes its form, not the chemica! composition. In rusting of iron, its chemical composition is changed.