Which process is the change from a liquid to a gas due to heat?

Which process is the change from a liquid to a gas due to heat?

• A. Melting
• B. Freezing
• C. Energy
• D. Evaporation

Answer: (D)

Heat adds energy to the liquid, increasing the motion of its molecules. Some surface molecules gain enough energy to overcome the attractive forces holding them in the liquid and they escape into the air as a gas. This gradual transformation from liquid to vapor at the surface is evaporation, a form of vaporization that can happen below the liquid’s boiling point. Melting and freezing are solid–liquid and liquid–solid changes, respectively, and energy by itself isn’t a process. So the described change from a liquid to a gas due to heat is evaporation.

Heat adds energy to the liquid, increasing the motion of its molecules. Some surface molecules gain enough energy to overcome the attractive forces holding them in the liquid and they escape into the air as a gas. This gradual transformation from liquid to vapor at the surface is evaporation, a form of vaporization that can happen below the liquid’s boiling point. Melting and freezing are solid–liquid and liquid–solid changes, respectively, and energy by itself isn’t a process. So the described change from a liquid to a gas due to heat is evaporation.