When a solid is heated, it turns into a liquid through a process called melting. When you cool that liquid down, the reverse process happens: freezing.

Here's what happens during freezing:

* Decreased Kinetic Energy: As the liquid cools, the molecules lose kinetic energy, which is the energy of motion. They start moving slower.

* Stronger Intermolecular Forces: With less kinetic energy, the intermolecular forces (the attractions between molecules) become stronger.

* Formation of a Lattice: The molecules slow down enough that they become fixed in a regular, repeating pattern called a lattice. This is the structure of a solid.

So, cooling a liquid causes it to solidify or freeze back into a solid.