Classify the following as physical and chemical changes:
(i) Eraser used for deleting pencil marks
(ii) Cooking of food items
(iii) Formation of clouds
(iv) Making ice candy
Physical change - (i), (iii), (iv); chemical change - (ii)
In a physical change, there is no change in the chemical composition of a substance, whereas, in a chemical change, the chemical nature of the substance changes because of formation of a new substance.
So, physical changes:
Eraser used for deleting pencil marks
Formation of clouds
Making ice candy
And, chemical change:
Cooking of food items, rusting of iron etc