Melting

Melting is the process in which a solid substance changes into a liquid state when heat is applied to it. This phase transition occurs when the temperature of the substance reaches its melting point.

Explanation:

1. Definition of melting:
Melting is a physical process that occurs when a solid substance is heated to a specific temperature, known as its melting point. At this temperature, the solid particles gain enough energy to overcome the forces holding them together in a fixed arrangement, causing them to break free and move more freely.

2. Melting point:
The melting point is the specific temperature at which a substance changes from a solid to a liquid. Each substance has its own unique melting point, which remains constant unless external conditions such as pressure are altered.

3. Process of melting:
When heat is applied to a solid substance, it causes the particles within the solid to vibrate more vigorously. This increase in energy disrupts the intermolecular forces between the particles, weakening their bonds. As the temperature continues to rise, the particles gain enough energy to break free from their fixed positions and move around more freely. The solid gradually loses its rigid structure and transforms into a liquid.

4. Examples of melting:
- Ice melting into water: When heat is applied to ice, it absorbs energy and its temperature increases. Once the temperature reaches 0 degrees Celsius, the ice begins to melt and transform into water.
- Candle wax melting: When a lit candle is left burning, the heat from the flame causes the wax to melt and become a liquid.

Summary:
Melting is the process in which a solid substance changes into a liquid state when heat is applied. It occurs when the temperature of the substance reaches its melting point, causing the solid particles to gain enough energy to break free from their fixed positions and move more freely.