What is the process by which a liquid changes to a gas at the surface?

What is the process by which a liquid changes to a gas at the surface?

• A. Evaporation
• B. Condensation
• C. Freezing
• D. Deposition

Answer: (A)

Evaporation is the process by which a liquid changes into a gas at the surface. At the boundary where the liquid meets the air, some molecules have enough kinetic energy to overcome the attractive forces binding them in the liquid and escape as vapor. This can happen even below the liquid’s boiling point, and it happens more quickly when the liquid is warmer, when the surface area is larger, or when there is better air movement to carry the vapor away. Condensation would be gas turning into a liquid, freezing is liquid turning into a solid, and deposition is gas turning directly into a solid, so they describe different phase changes.

Evaporation is the process by which a liquid changes into a gas at the surface. At the boundary where the liquid meets the air, some molecules have enough kinetic energy to overcome the attractive forces binding them in the liquid and escape as vapor. This can happen even below the liquid’s boiling point, and it happens more quickly when the liquid is warmer, when the surface area is larger, or when there is better air movement to carry the vapor away. Condensation would be gas turning into a liquid, freezing is liquid turning into a solid, and deposition is gas turning directly into a solid, so they describe different phase changes.