When the temperature of substance
decreases, what happens to the
substances thermal energy?

Explanation:

When a substance is heated, it gains thermal energy. Therefore, its particles move faster and its temperature rises. When a substance is cooled, it loses thermal energy, which causes its particles to move more slowly and its temperature to drop.

When the temperature of a substance is increased, i.e., if you double the Kelvin temperature of a substance, you double the average kinetic energy of its molecules. When the average kinetic energy of the molecules goes up (a rise in temperature), the average speed of the molecules increases.

practical process described pest part of scientific investigation.

because practical knowledge is powerful then therotical knowledge.

c8h10 is your answerr