Question

which example is a physical change? a rusting of a nail b burning of fuel c breaking of glass d ripening of fruit

Explanation:

To determine a physical change, we check if the substance's chemical identity remains the same (only physical properties like shape, size change).

• Option a: Rusting of a nail involves iron reacting with oxygen to form rust (new substance, chemical change).
• Option b: Burning fuel produces new substances (like CO₂, H₂O), chemical change.
• Option c: Breaking glass only changes its size/shape; no new substance is formed (physical change).
• Option d: Ripening fruit involves biochemical reactions (new substances, chemical change).

Answer:

c. breaking of glass