Which of the following are chemical changes?
  1. Decaying of wood
  2. Burning of wood
  3. Sawing of wood
  4. Hammering of a nail into a piece of wood

  5. (a) (i) and (ii)
    (b) (ii) and (iii)
    (c) (iii) and (iv)
    (d) (i) and (iv)

AcademicChemistryNCERTClass 9

Correct answer: (a) (i) and (ii)  

Explanation: Decaying and burning of wood are chemical changes as in these processes, the chemical composition of wood is changed and a new substance is formed, that cannot be converted back into its original form.

Updated on 10-Oct-2022 13:29:32