Question

Explain why burning of wood and cutting it into small pieces are considered as two different types of changes.
NCERT Solutions for Class 7th Science Chapter 6 Physical and Chemical Changes Page 66 Exercise Question 7

Answer 1

Burning of wood is considered as a chemical change. It's so because burning of wood changes the chemical composition of wood and changes it into ash whereas on the other hand cutting of wood is a physical change because it doesn't change the chemical composition of wood. In this case wood is only cut down into smaller pieces but it still remains the same but doesn't change into ash or any other thing.

Answer 2

Answer:

Burning of wood is a chemical change while cutting of wood is a physical change because during burning, new substances are formed. After burning, we cannot get original substance, (i.e. wood) back. Cutting of wood into small pieces is a physical change because no new substance is formed.