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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
Options
(i) and (ii)
(ii) and (iii)
(iii) and (iv)
(i) and (iv)
Solution
(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.
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