Which statement describes evaporation?

Which statement describes evaporation?

• A. Liquid to vapor by removing heat
• B. Liquid to vapor by adding heat
• C. Vapor to liquid by removing heat
• D. Liquid to solid by adding heat

Answer: (B)

Evaporation happens when a liquid becomes a gas as energy is added to the liquid. When heat is supplied, molecules at the surface gain enough energy to break free from the liquid and enter the vapor phase. This can occur at any temperature below the boiling point, and it happens mainly at the surface of the liquid. The rate increases with higher temperature, larger surface area, more air flow over the surface, and lower surrounding humidity. This is different from condensation, which is vapor turning into liquid when energy is removed, and from freezing, which is liquid turning into a solid when energy is removed. So the statement that describes evaporation is liquid turning into vapor by adding heat.

Evaporation happens when a liquid becomes a gas as energy is added to the liquid. When heat is supplied, molecules at the surface gain enough energy to break free from the liquid and enter the vapor phase. This can occur at any temperature below the boiling point, and it happens mainly at the surface of the liquid. The rate increases with higher temperature, larger surface area, more air flow over the surface, and lower surrounding humidity.

This is different from condensation, which is vapor turning into liquid when energy is removed, and from freezing, which is liquid turning into a solid when energy is removed. So the statement that describes evaporation is liquid turning into vapor by adding heat.