Answer: contracts on heating.
- A contracts on heating
- B expands on heating
- C stays the same
- D turns to vapour
Correct answer: A. contracts on heating
Explanation: Unusually, water contracts as it warms from 0°C to 4°C, then expands above 4°C.
During a phase change (melting or boiling), temperature stays constant while heat is absorbed entirely as latent heat (Q=mL); temperature only rises again once the substance is fully in its new phase.
Concept context
Temperature scales, thermal expansion, calorimetry, and the three modes of heat transfer including radiation laws.