Evaporation refers to heat transfer through which process?

Evaporation refers to heat transfer through which process?

• A. Phase change from liquid to vapor
• B. Direct contact
• C. Flood of fluids
• D. Radiation

Answer: (A)

Evaporation is heat transfer that occurs when molecules at the surface of a liquid gain enough energy to break free into the gas phase. This is a phase change from liquid to vapor, which requires latent heat of vaporization. The energy absorbed from the surroundings as evaporation occurs cools the liquid surface, a principle used in sweating to dissipate heat. The other options describe different heat-transfer modes: direct contact means conduction, radiation is heat transfer by electromagnetic waves without a phase change, and a flood of fluids isn’t a recognized mechanism. So evaporation is the phase-change process from liquid to vapor.

Evaporation is heat transfer that occurs when molecules at the surface of a liquid gain enough energy to break free into the gas phase. This is a phase change from liquid to vapor, which requires latent heat of vaporization. The energy absorbed from the surroundings as evaporation occurs cools the liquid surface, a principle used in sweating to dissipate heat. The other options describe different heat-transfer modes: direct contact means conduction, radiation is heat transfer by electromagnetic waves without a phase change, and a flood of fluids isn’t a recognized mechanism. So evaporation is the phase-change process from liquid to vapor.