Which of the following are chemical changes?

1. Chemical Changes:
– Rusting of iron (b):
– Involves a chemical reaction between iron, oxygen, and water, leading to the formation of iron oxide (rust).

– Cooking of food (d):
– Various chemical changes occur during cooking, including the Maillard browning reaction, caramelization, and denaturation of proteins.

– Digestion of food (e):
– A complex process where food undergoes chemical changes, breaking down into simpler substances with the help of digestive enzymes.

– Burning of a candle (g):
– Involves a chemical reaction between the wax and oxygen, producing carbon dioxide and water vapor.

2. Physical Changes:
– Growth of a plant (a):
– Biological process, not involving a fundamental chemical change in the plant.

– Mixing of iron filings and sand (c):
– Physical change, as no new substances are formed.

– Freezing of water (f):
– A physical change where water changes its state from a liquid to a solid without altering its chemical composition.