What is the total energy of motion of the molecules of a substance called?

The answer to this is C. You need to remember that the movement of the small particles can cause heat. For example, when you bring water to a boil, water becomes hotter because the molecules of water keep on moving around until the boiling point is reached. This is the same with all the other types of matter that you can find in this world whether they are solid, liquid, or gas.

Temperature is the measurement of how hot or how cold the object is. Heat is known as the transfer of one hot molecule to a cold molecule so that it can also become hot. The thermometer is the device that you will use to measure the temperature.