What causes thermal energy to change?

Temperature causes changes in the amounts of thermal energy held by a substance or system. The higher the temperature, the higher the amount of thermal energy held.

The thermal energy of an object is due to the movement of the particles that constitute it. These particles can be atoms, molecules or electrons. When thermal energy is transferred from one object to another, it is known as heat. A practical example of thermal energy is a pot on a stove. As the heating coil temperature increases, its thermal energy increases. The thermal energy transfers from the coil to the pot, and from the pot to the water, resulting in hot water.