Here's why:

* Solids: The molecules in a solid are closely packed and have a fixed arrangement. Cooling a solid reduces the kinetic energy of the molecules, making them vibrate less. This causes a slight decrease in volume, but the change is usually minimal compared to liquids.

* Liquids: Liquids have molecules that are more loosely packed than solids and can move around more freely. When cooled, the molecules slow down and move closer together, resulting in a more significant contraction in volume.

* Gases: Gases are highly compressible due to their widely spaced molecules. Cooling a gas causes the molecules to slow down and collide less frequently, leading to a significant decrease in volume. However, the change in volume for a gas is typically much larger than for a liquid or solid.

Exceptions:

While liquids generally contract more than solids when cooled, there are some exceptions:

* Water: Water is unique because it expands when cooled from 4°C to 0°C. This is due to the formation of hydrogen bonds between water molecules.

* Amorphous solids: These solids don't have a fixed crystalline structure like regular solids. Their behavior can sometimes be closer to liquids, and they may exhibit more significant contraction upon cooling.

In summary: Although gases experience the largest volume changes with temperature, liquids usually contract more than solids when cooled.