Which of the following physical changes is endothermic?

• A. Condensation of water vapor
• B. Freezing of water
• C. Deposition of carbon dioxide
• D. Melting of ice

Answer: (D)

Verified step by step guidance

1. Understand the meaning of an endothermic physical change: it is a process that absorbs heat from the surroundings.
2. Recall that melting of ice involves changing solid water (ice) into liquid water, which requires energy input to break the hydrogen bonds holding the solid structure together.
3. Recognize that condensation, freezing, and deposition are all processes where a substance changes from a higher-energy phase to a lower-energy phase, releasing heat (exothermic).
4. Identify that melting is the only process listed that requires heat absorption to overcome intermolecular forces, making it endothermic.
5. Conclude that among the options, melting of ice is the endothermic physical change because it absorbs heat to transition from solid to liquid.