How do refrigerants absorb heat during their cooling cycle?

Refrigerants absorb heat during their cooling cycle primarily through the process of evaporation, which occurs when the refrigerant changes state from a liquid to a vapor. During this phase shift, the refrigerant requires heat energy to break the intermolecular bonds holding the liquid together. This energy is absorbed from the surroundings, such as the air or water that needs to be cooled.

As the refrigerant evaporates, it captures heat from the environment, thus lowering the temperature of the space being cooled. This principle is fundamental to the operation of refrigeration systems, where the ability of the refrigerant to absorb heat during evaporation is crucial in maintaining the cooling effect.

The other options refer to different processes within the refrigeration cycle, but they do not describe how heat absorption occurs. For instance, condensation, which happens when vapor turns to liquid, involves the release of heat rather than absorption. Transferring heat to the environment occurs during the condensing phase as well, and compressing gas molecules relates more to increasing pressure and temperature rather than heat absorption.