In the 1840s scientists understood that heat was not just a substance but a form of energy that can be converted from one form to another. James Prescott Joule and Rudolf Clausius stated that heat can produce mechanical energy, and mechanical energy can produce heat. Which leads to the idea that the “heat energy” of a substance is the kinetic energy of its atoms and molecules. Heat is what makes kinetic energy. The more heat that is produced the higher the kinetic energy level of an object or substance is or has. The kinetic energy theory of matter is a scientific theory that states that matter consists of small particles in a rapid random motion. The kinetic energy theory gives the differences of three states of matter: solids, liquids, and gases. The Kinetic Theory of Matter states that matter is composed of a large number and small particles that are in constant motion. It also assumes that particles are small and widely separated. They collide and exchange energy. The theory helps explain the flow or transfer of heat and the relationship between pressure, temperature and volume properties of gases. Heat is energy and describes the movement between objects. Heat is a measure of the total internal energy that has been absorbed or transferred from one body to another. Internal energy is the kinetic and potential energy of molecules of an object. The total internal energy of molecules increases by gaining energy from a temperature difference such as conduction, convection and radiation or by gaining energy from a form conversion (mechanical, chemical radiant, electrical, nuclear). Heat is a form of energy that is mostly converted into kinetic energy of molecules. As long as you heat an object, its temperature rises.