When a solid is heated, it undergoes a phase change called melting, which results in the formation of a liquid. This process can be explained in detail as follows:
1. Introduction:
- When a solid is heated, the energy is transferred to its atoms or molecules, causing them to vibrate more rapidly.
- As the temperature continues to increase, the kinetic energy of the particles also increases.
2. Melting Point:
- Every substance has a specific temperature at which it changes from solid to liquid. This temperature is known as the melting point.
- When the temperature reaches the melting point of a solid, its particles gain enough energy to overcome the attractive forces holding them together.
3. Breaking of Bonds:
- The heat energy supplied breaks the intermolecular forces or bonds between the particles.
- These forces can be ionic, covalent, or metallic in nature, depending on the type of solid.
4. Arrangement of Particles:
- In a solid state, the particles are arranged in a regular pattern, which gives them a fixed shape and volume.
- As the solid is heated and melts, the particles gain enough energy to move more freely, leading to an increase in disorder.
5. Liquid Formation:
- Once the bonds are broken, the solid transforms into a liquid state.
- In the liquid state, the particles have more kinetic energy and are able to move past one another, resulting in a fluid substance.
6. Properties of the Liquid:
- The liquid formed from the melted solid has a definite volume but takes the shape of its container.
- It exhibits properties such as surface tension, viscosity, and the ability to flow.
In conclusion, when a solid is heated, it melts to form a liquid. This phase change occurs when the particles gain enough energy to break their bonds and transition into a more disordered state.