Classify the following examples into physical or chemical change. [1 MARK]

1) Photosynthesis and burning of coal

2) Dissolving sugar in water and melting of wax

Classify the changes involved in the following processes as physical or chemical changes:

(a) Photosynthesis

(b) Dissolving sugar in water

(c) Burning of coal

(d) Melting of wax

(e) Beating aluminium to make aluminium foil

(f) Digestion of food

Classify these changes into physical and chemical changes. [5 MARKS]

Question 4

(c) Classify the following processes into physical or chemical changes.
baking of bread, switching of an electric bulb, curdling of milk, dissolving sodium chloride in water, photosynthesis, rusting of iron, evaporation of water, formation of dew, sublimation of camphor, burning of charcoal or LPG, clotting of blood, crystallization of sugar, ripening of fruit, cooking of vegetables, melting of wax.

Classify the following as a physical or a chemical change :

(a) Drying of wet clothes

(b) Manufacture of salt from sea water.

(c) Butter getting rancid

(d) Boiling of water

(e) Burning of paper

(f) Melting of wax

(g) Burning of coal