Question

Give examples to explain the difference between changes that can or cannot be reversed.

Answer 1

Burning of paper can't be reversed
but the burning of candle can be reversed by its wax

Answer 2

(i) Paper can be folded to make different shapes. This is reversible change as shapes of paper can be unfolded back into paper sheet. But when paper is burnt and turned into ash, it can't be reversed.

(ii) If we fill balloon with air, the shape and size of the balloon changes. This change can be reversed but if balloon burst while inflating then this change can't be reversed.

(iii) The shape of rubber band can be changed by stretching which can be reversed