Question

Which of the following are chemical changes?

(i) Decaying of wood

(ii) Burning of wood

(iii) Sawing of wood

(iv) Hammering of a nail into a piece of wood

विकल्प

• (i) and (ii)

• (ii) and (iii)

• (iii) and (iv)

• (i) and (iv)

Answer 1

(i) and (ii)

Explanation: 

Decaying of wood and burning of wood are chemical changes since there is a change in the chemical composition of wood. Sawing of wood and hammering of a nail into a piece of wood are physical changes since there is no change in the composition of the wood during these changes.