The thermal energy of a substance is directly related to its kinetic energy. Thermal energy is the total kinetic energy of all the particles in a substance, including the random motion of atoms and molecules. As a substance's temperature increases, the kinetic energy of its particles also increases, leading to higher thermal energy. Conversely, when a substance loses thermal energy (such as when it cools down), its kinetic energy decreases. Therefore, the relationship between a substance's thermal energy and its kinetic energy is direct and closely linked.
