Question

Match the following.

(a) Evaporation of water	(i) Non-periodic change
(b) Milk turning sour	(ii) Periodic change
(c) Earthquake	(iii) Chemical change
(d) Change of seasons	(iv) Physical change
(e) Glowing of bulb	(v) Reversible change

Answer 1

Evaporation involves the conversion of water into its vapours. This is a physical change.
(a) Evaporation of water – (iv) Physical change
It is a reversible change also.

When milk becomes sour, a new substance will be formed. This is a chemical change.
(b) Milk turning sour - (iii) Chemical change

Earthquake is an undesirable change that does not repeats over a regular interval of time. It is a non-periodic change.
(c) Earthquake - (i) Non-periodic change

Change of seasons repeats over a regular interval of time. Hence, it is a periodic change.
(d) Change of seasons - (ii) Periodic change

Glowing of bulb is a reversible change as we can glow a bulb and switch it off.
(e) Glowing of bulb - (v) Reversible change
It is a physical change also.