Step-by-step explanation:
In a liquid, atoms are less strongly held together as compared to solids. Due to this the atoms are able to slide past each other.
But when liquids are cooled at a certain temperature then their atoms come closer to each other. As a result, they are held by strong forces due to which liquid phase changes into solid phase.
For example, water freezes at zero degree celsius.
Thus, we can conclude that a liquid cooled down below a certain temperature becomes a solid as it freezes.