When a gas is cooled, the particles begin to move /slowly). when the temperature drops below (melting point/boiling point), the substance's particles have condensed and formed a liquid. if the liquid is cooled down even more, the amount of thermal energy in the particles /decrease), and the liquid's temperature will continue to decrease. eventually, the substance will freeze and form a solid. if the temperature continues to (increase/decrease), the particles in the solid (vibrate in place/move around one another) more slowly.