What kind of heat causes a substance to change state without changing temperature?

The type of heat that causes a substance to change state without changing temperature is known as latent heat. This term specifically refers to the energy absorbed or released during a phase change, such as melting, freezing, vaporization, or condensation. During these processes, the temperature of the substance remains constant even though energy is being added or removed. For example, when ice melts into water, it absorbs heat (latent heat of fusion) without an increase in temperature until the entire solid phase has transformed into a liquid.

Understanding this concept is crucial in thermodynamics and engineering, as it has significant implications in processes involving refrigeration, heating, and natural phenomena. Sensible heat, on the other hand, does cause a change in temperature without a phase change, while thermal energy generally refers to the total energy due to the motion of particles in a substance, and specific heat is a property that defines how much heat energy is required to change the temperature of a substance by one degree Celsius.