The temperature of a pure substance remains constant while it is melting, even though energy is still being supplied. Why is this?
Question 1 Report
The temperature of a pure substance remains constant while it is melting, even though energy is still being supplied. Why is this?
Answer Details
During melting, a substance changes from solid to liquid. The particles in a solid are held in fixed positions by intermolecular forces. To convert the solid into a liquid, these forces must be partially overcome so that particles can move more freely.
The energy being supplied during melting is used entirely to break or weaken these intermolecular bonds. This energy is called the latent heat of fusion. Because the energy goes into changing the arrangement of particles rather than increasing their speed, the average kinetic energy of the particles does not increase, and the temperature remains constant.
The substance has not reached any 'maximum temperature' - once melting is complete, further heating will raise the temperature again. The explanation is not about energy losses balancing gains either; it is specifically about the energy being redirected to overcome intermolecular forces.
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