In a phase diagram of water, which process occurs when water changes to ice?

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

Answer: (B)

Verified step by step guidance

1. Understand the phase diagram of water, which shows the states of water (solid, liquid, gas) and the transitions between these states under different temperature and pressure conditions.
2. Identify the process where water changes from liquid to solid. This is the transition from the liquid phase (water) to the solid phase (ice).
3. Recall the terminology for phase changes: melting is solid to liquid, freezing is liquid to solid, sublimation is solid to gas, and condensation is gas to liquid.
4. Since the problem states water changes to ice, this corresponds to the liquid-to-solid transition, which is called freezing.
5. Therefore, the process occurring when water changes to ice on the phase diagram is freezing.