Change in State of Matter without Change in Temperature
Changing the state of matter from solid to liquid, liquid to gas, or vice versa does not involve a change in temperature. This process is known as a phase change, and it occurs at a specific temperature known as the melting point, boiling point, or condensation point.

Explanation:
- When a substance changes its state from solid to liquid (melting) or liquid to gas (vaporization), the temperature remains constant until all the solid has melted or all the liquid has vaporized. This is because the energy being added is used to break the intermolecular forces holding the particles together, rather than increasing their kinetic energy (temperature).
- Similarly, when a substance changes its state from gas to liquid (condensation) or liquid to solid (freezing), the temperature remains constant until all the gas has condensed or all the liquid has solidified. In this case, the energy being released is used to form intermolecular forces between the particles, rather than decreasing their kinetic energy.
- This phenomenon is known as latent heat, where energy is absorbed or released during a phase change without a change in temperature. The amount of heat absorbed or released is specific to each substance and is known as the heat of fusion or heat of vaporization.
In conclusion, a change in the state of matter involves a transfer of energy to break or form intermolecular forces, resulting in a phase change without a change in temperature.