What is the process of evaporation?

Evaporation is the process in which liquid water transforms into water vapor, which is a gas. This occurs when molecules in the liquid gain enough energy to overcome intermolecular forces and break free into the air as gas. It typically happens at the surface of the liquid, and can occur at any temperature, although it occurs more rapidly at higher temperatures. This process is crucial in the water cycle, contributing to the condensation and precipitation processes that sustain ecosystems.

The other options refer to different physical processes. One describes the freezing of water, while another discusses how plants absorb water, which is related to transpiration rather than evaporation itself. The final option mentions pollution, which is unrelated to the phase change of water. Therefore, the option that accurately defines evaporation is the transformation of water from a liquid state to a gaseous state.