Which change takes place at the freezing point of a substance?

• A. The solid turns into a gas.
• B. The gas turns into a liquid.
• C. The solid turns into a liquid.
• D. The liquid turns into a solid.

Answer: (D)

Verified step by step guidance

1. Understand that the freezing point of a substance is the temperature at which it changes from a liquid to a solid.
2. Recall the phase changes: melting (solid to liquid), freezing (liquid to solid), vaporization (liquid to gas), condensation (gas to liquid), sublimation (solid to gas), and deposition (gas to solid).
3. Identify that at the freezing point, the process occurring is the transition from liquid phase to solid phase.
4. Note that the reverse process of freezing is melting, which occurs at the melting point, the same temperature as the freezing point but in the opposite direction.
5. Conclude that the correct change at the freezing point is 'the liquid turns into a solid.'