What is the process called when liquid water changes into vapor?

The process in which liquid water transforms into vapor is known as evaporation. This occurs when water molecules at the surface gain enough energy, typically from heat, to break free from the liquid state and enter the gaseous state. Evaporation is a critical component of the water cycle, allowing water from oceans, lakes, and rivers to move into the atmosphere as vapor.

Understanding this process also ties into concepts such as temperature and humidity, as warmer temperatures generally increase the rate of evaporation by providing more energy to the water molecules. This phase change can happen at any temperature when liquid water is exposed to air, not just when it reaches its boiling point.