Why do liquids have a higher thermal expansion coefficient than solids?

Liquids have a higher thermal expansion coefficient than solids due to their weaker intermolecular forces and greater freedom of movement.

In more detail, the thermal expansion of a substance is determined by the strength of the forces between its particles and the amount of space they have to move. In solids, the particles are tightly packed together and held in place by strong intermolecular forces. This means that when heat is applied, the particles vibrate more but cannot move far from their positions, resulting in a relatively small increase in volume.

On the other hand, the particles in liquids are not as tightly packed and are held together by weaker intermolecular forces. This gives them more freedom to move around. When heat is applied to a liquid, its particles not only vibrate more but also move further apart from each other. This results in a larger increase in volume, hence a higher thermal expansion coefficient.

Furthermore, the weaker intermolecular forces in liquids mean that a smaller amount of heat energy is required to increase the movement of the particles. This is another reason why liquids expand more than solids for a given increase in temperature.

In summary, the higher thermal expansion coefficient of liquids compared to solids is due to their weaker intermolecular forces and greater freedom of movement. This allows the particles in a liquid to move further apart when heat is applied, resulting in a larger increase in volume.