Which term describes a change of state from liquid to gas?

• A. Conduction
• B. Evaporation
• C. Condensation
• D. Sublimation

Answer: (B)

Moving from a liquid to a gas is vaporization, and when it happens at the surface at temperatures below the boiling point it’s called evaporation. In evaporation, individual molecules at the liquid’s surface gain enough energy to overcome the intermolecular forces holding them in the liquid and escape into the air as vapor. This process cools the remaining liquid because the higher-energy molecules are preferentially leaving. The rate of evaporation increases with higher temperature, greater surface area, lower humidity, and more airflow.

Other terms describe different things: condensation is gas turning back into liquid, sublimation is solid turning directly into gas, and conduction refers to heat transfer between substances, not a phase change.