. An example of a chemical and irreversible change is
(a) dissolving salt in water.
(b) rotation of a fan.
(c) making of a paper aeroplane.
(d) growth of a plant.
Explanation- Growth of a plant is a slow, irreversible and chemical change as it occurs naturally. It takes longer time to occur and cannot be reversed into small plant or seed. During the growth of a plant, new substances are formed which cannot be reversed into previous ones.