Answer: Decreases.
- A Increases
- B Decreases
- C Remains constant
- D First increases then decreases
Correct answer: B. Decreases
Explanation: Wiens law states λ_m·T = constant, so as T increases, the peak wavelength λ_m decreases (shifts toward blue/shorter wavelengths).
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.