question_answer 21)

Which of the following are chemical changes? (a) Growth of a plant             (b) Rusting of iron (c) Mixing of iron filings and sand         (d) Cooking of food (e) Digestion of food                       (f) Freezing of water (g) Burning of a candle  

Answer:

(a) Growth of a plant, (b) rusting of iron, (d) cooking of food, (e) digestion of food and (g) burning of a candle, are chemical changes.