Why does the temperature of a substance remain constant during a phase change (e.g., melting or boiling), even though heat is continuously supplied?
BiologyClass 9CBSEAnswered 12 May 2026
Answer
The temperature of a substance remains constant during a phase change because the heat energy supplied at that point is used to overcome the intermolecular forces of attraction between the particles, rather than increasing their kinetic energy. This energy is known as latent heat.
For instance, during melting, latent heat of fusion breaks the bonds holding solid particles in fixed positions, allowing them to move as a liquid. During boiling, latent heat of vaporization separates liquid particles into the gaseous state.
Until all of the substance has undergone the phase change, the temperature will not rise.
Suggested Q&A
Biology · Class 9- BiologyClass 9A boy runs along a circular track of radius 7 meters. If he completes one full round in 22 seconds, calculate his average speed and the magnitude of his average velocity for this round.
- BiologyClass 9What is the function of stomata in the epidermis of plant leaves?
- BiologyClass 9Describe the general characteristics of connective tissues that set them apart from other animal tissues.
- BiologyClass 9Distinguish between primary growth and secondary growth in plants, indicating which meristems are responsible for each.
- BiologyClass 9What is the role of intercalated discs in cardiac muscle tissue?
- BiologyClass 9Enlist the major types of cells found in blood and their specific functions.