Exothermic phase changes release heat energy

Steps:

• Exothermic processes release heat to the surroundings during physical changes like phase transitions.
• Identify exothermic changes: freezing (liquid to solid) and condensation (gas to liquid) release heat as particles form stronger bonds.
• Identify endothermic changes: melting (solid to liquid) and evaporation (liquid to gas) absorb heat to break bonds.
• Evaluate options: only C pairs two exothermic processes.

Why C is correct:

• Freezing and condensation are exothermic per the definition of phase changes where decreased molecular disorder releases thermal energy, following the second law of thermodynamics.

Why the others are wrong:

• A: Evaporation absorbs heat (endothermic).
• B: Both evaporation and melting absorb heat (endothermic).
• D: Melting absorbs heat (endothermic).

Final answer: C