Answer: surroundings.
- A surroundings
- B body itself
- C absolute zero
- D boiling point
Correct answer: A. surroundings
Explanation: T₀ is the surrounding temperature that the body also absorbs radiation from.
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.