What is 'latent heat' in the context of phase changes?

Latent heat refers to the amount of heat absorbed or released by a substance during a phase change without a change in temperature. In the case of water turning into steam, this process involves the absorption of heat, known as latent heat of vaporization, which allows water molecules to overcome the intermolecular forces that hold them together in the liquid state. This absorption of heat leads to a phase change from liquid to gas, while the temperature of the water remains constant until all the water has transformed into steam.

The significance of this concept lies in its application in various fields, including meteorology, engineering, and culinary processes. By recognizing that latent heat is effectively “hidden” during the phase transition, one grasps how energy transfers occur in different states of matter. This understanding allows for better predictions and management of heat transfer in practical applications, such as designing boilers and understanding weather patterns.

Other options, while discussing heat in various contexts, do not encapsulate the essence of latent heat during phase changes. For instance, heat absorbed during freezing, extra heat for raising temperature, and heat lost when cooling refer to different processes where temperature changes occur rather than phase changes without temperature shifts.