Answer: convection.
- A conduction
- B thermal expansion only
- C radiation
- D convection
Correct answer: D. convection
Explanation: Bulk movement of warm and cool air masses transfers heat by convection.
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.