# The Kinetic Theory of Matter and Thermodynamics

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The kinetic theory of matter is a collection of assumptions about the small particles of matter and the space around them that traces back to the fifth century B.C. when Democritus first wrote about it. This idea was later accepted by Galileo and Newton, however widespread acceptance of the theory did not occur until strong evidence was presented in the late 1700s and early 1800s (Tillery, 2009). The kinetic theory of matter states that matter is composed of a large number of tiny particles consisting of individual molecules that are in constant motion. A molecule is defined as the smallest particle of a compound or a gaseous element that can exist and still retain the characteristic properties of that substance (Bellis, 2011). The kinetic theory of matter plays a large role in the study of heat because the temperature of matter affects the average kinetic energy of the particles.
The Kinetic Theory of Matter describes heat transfer by conduction, where thermal energy appears to move through a material, warming up cooler areas. Heat is energy that is measured in Joules or other energy units; it is a measurement of some of the energy in a substance that moves between two objects of a different temperature .This process is called heat transfer or heat flow (Tillery, 2009). If you add heat to a substance, then this means you are adding energy to the substance. This added heat (energy) is usually expressed as an increase in the kinetic energies of the molecules of the substance. If the heat (energy) is used to change the state of the substance, say by melting it, then the added energy is used to break the bonds between the molecules rather than changing their kinetic energy.
Temperature is related to heat because it is expressed as a number that relates to a type of energy, like heat, possessed by the molecules of a substance. In this way, temperature directly
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relates to the kinetic energy of the molecules (Jones, 2011). Temperature can be measured in a...