AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
(b) Change in shape
The textbook states that change in colour, evolution of a gas, and change in temperature are indicators of a chemical reaction. Change in shape is a physical change, not a chemical one.
Source: Chapter 1, Chemical Reactions and Equations (Activity 1.1–1.3)
The NCERT text explicitly lists four indicators: change in state, change in colour, evolution of gas, and change in temperature. "Change in shape" is a physical change (like cutting or moulding) and does NOT indicate a chemical reaction. Examiners expect you to recall this list directly from the chapter introduction.