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
(j) Freezing of water
(g) Burning of a candle
Growth of a plant, Rusting of iron, Cooking of food, Digestion of food and Burning of a candle are chemical changes.
Chemical change brings change in the chemical properties of matter and a new substances is formed. A chemical change is also called a chemical reaction. All of the above changes have resulted in the formation of new substances as a result of chemical reactions.