Which change of state involves a release of energy?

• A. Melting
• B. Boiling
• C. Condensation
• D. Sublimation

Answer: (C)

Verified step by step guidance

1. Understand that changes of state (phase changes) involve either absorption or release of energy, typically in the form of heat.
2. Recall that melting (solid to liquid), boiling (liquid to gas), and sublimation (solid to gas) are processes that require energy input to overcome intermolecular forces, so they absorb energy.
3. Recognize that condensation (gas to liquid) is the reverse of boiling, where gas particles lose energy and come closer together, releasing energy to the surroundings.
4. Therefore, identify that condensation is a change of state that involves the release of energy.
5. Summarize that phase changes from higher energy states to lower energy states (like gas to liquid or liquid to solid) release energy, while changes from lower to higher energy states absorb energy.