Physical change – A substance is said to undergo a physical change when only the physical properties such as the shape, size, colour, state or appearance of the substance change. Its chemical composition remains intact.
Chemical change – A substance is said to undergo a chemical change when the chemical properties of a substance alter. As a result, there is either formation or breaking of atomic bonds at the molecular level.
(a) Photosynthesis – Chemical change
(b) Dissolving sugar in water – Physical Change
(c) Burning of coal – Chemical change
(d) Melting of wax – Physical Change
(e) Beating aluminium to make aluminium foil – Physical Change
(f ) Digestion of food – Chemical change