Freezing

Definition

Freezing is the phase transition from the liquid state to the solid state. It occurs when a liquid's temperature is lowered below its freezing point.

5 Must Know Facts For Your Next Test

1. The freezing point of a substance is the temperature at which it changes from a liquid to a solid under standard atmospheric pressure.
2. During freezing, the kinetic energy of the molecules decreases, causing them to arrange into a fixed, orderly structure.
3. Water has an unusual freezing point of 0°C (32°F) due to hydrogen bonding.
4. Freezing is an exothermic process, meaning it releases heat into the surroundings.
5. Supercooling can occur when a liquid remains in its liquid state below its normal freezing point without forming a solid.

Review Questions

• What happens to the kinetic energy of molecules during the freezing process?
• Why is freezing considered an exothermic process?
• What is supercooling and how does it relate to freezing?

Related terms

Melting: The phase transition from a solid state to a liquid state, occurring at the melting point.

Boiling Point: The temperature at which a liquid changes to gas under standard atmospheric pressure.

Sublimation: The phase transition where a substance changes directly from a solid to a gas without passing through the liquid phase.