Question

When a gas is cooled, the particles begin to move more______(Quickly/slowly). When the temperature drops below the____ (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 will____(increase/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 will____ (Vibrate in place/move around one another) more slowly.

Answer 1

Slowly; Boiling Point; Decrease; Decrease; Vibrate in place.

As temperature drops, so does thermal energy, and particle motion drops. The same trends in temperature, thermal energy, and motion applys to phases in decreasing order: gas>liquid>solid. The particle motion is always vibrations in place for solids because they are very tightly packed compared to liquids and gases.