Question

Match the columns:

	I		II
(a)	Physical change	(i)	Curdling of milk
(b)	Chemical change	(ii)	Demagnetisation of magnets
		(iii)	Digestion of food
		(iv)	Crystallisation of substance
		(v)	Rusting of iron

• A. a: i, ii, iii; b: iv, v
• B. a: ii, iv; b: i, iii, iv
• C. a: ii, iv; b: i, iii, v
• D. a: iii, v; b: i, ii, iv

Answer 1

Answer: (C)

a: ii, iv; b: i, iii, v

A change in which only the physical properties of the substance are changed, while its chemical composition remains unchanged, is called a physical change. Crystallisation of substance and demagnetisation of magnets come under this change.

A change in which chemical composition and chemical properties of the reacting substances undergo a change is called a chemical change.
For eg., curdling of milk, digestion of food, rusting of iron