What is the primary process by which heat is lost when a liquid turns into a gas?

The correct answer is evaporation, which is the primary process by which heat is lost when a liquid turns into a gas. During evaporation, molecules in the liquid gain enough energy to overcome the intermolecular forces holding them together and transition into the gaseous state. This process requires energy, which is drawn from the surrounding environment, resulting in a cooling effect. Essentially, as the high-energy molecules escape into the gas phase, the average energy of the remaining liquid decreases, leading to a loss of heat.

In contrast, condensation refers to the process where gas turns back into a liquid, releasing heat into the surrounding environment. Subduction relates to tectonic plate movements and does not pertain to the phase transition of liquids and gases. Solidification, or freezing, is the transition from a liquid to a solid and also results in heat release, but it is not the process of heat loss associated with the conversion of a liquid to a gas.