cooling matter causes the particles to

Cooling matter causes the particles to slow down, lose kinetic energy, and move closer together, so the substance usually contracts and can change to a more rigid state (like liquid to solid).

What happens to particles when cooled

• Particles lose thermal (heat) energy, so their kinetic energy decreases and they move more slowly.

• As they slow, attractive forces pull them closer, so the particles become more tightly packed and the material contracts.

• In many substances this cooling can change state: gases condense to liquids and liquids can freeze into solids as motion drops enough for fixed structures to form.

One-sentence fill-in answer

For a typical textbook fill‑in, the completed idea is:

“Cooling matter causes the particles to slow down and move closer together.”