It is used to overcome the forces of attraction between the particles.
Explanation
The transition from a solid to a liquid state occurs at a specific temperature called the melting point. The heat energy absorbed by a unit mass of a substance to change its state without a change in temperature is known as the Latent Heat of Fusion.
Detailed Analysis:
- Utilization of Heat Energy: During the melting process, the temperature of the substance remains constant until the entire solid has turned into liquid. Since temperature is a measure of the average kinetic energy of particles, the kinetic energy does not increase during this phase.
- Overcoming Intermolecular Forces: The heat supplied is utilized to weaken and overcome the strong forces of attraction holding the particles in the solid lattice structure. This allows the particles to move away from their fixed positions and flow as a liquid.
- Internal Energy Change: This energy is stored in the substance as potential energy, representing the work done against the attractive forces.
- Incorrect Options:
- It increases the kinetic energy of the particles, raising the temperature. is incorrect because an increase in kinetic energy would result in a temperature rise, which does not happen during the phase change.
- It is radiated back to the surroundings immediately. is incorrect because the heat is absorbed by the substance to facilitate the state change, not radiated back.
- It is converted into potential energy of the container. is incorrect because the energy change pertains to the internal energy of the substance, not the container.
Key Takeaway:
During a phase change (such as melting), supplied heat is known as Latent Heat. It is used exclusively to overcome intermolecular forces of attraction, increasing the potential energy of the system while the temperature (kinetic energy) remains constant.