The Kinetic Molecular Theory of Matter describes the composition of the atoms in matter and their behavior that lead to their observable properties. This theory also describes the motions of the molecules in different states of matter, and how these molecules behave during phase changes. This theory can be summarized in 6 key points:
1. All matter is made up of moving atoms.
2. All atoms contain energy, but it differs on the state. Solids have the least amount of energy, that's why they hardly move in their places. If they do, these are just vibrations. Fluids, like liquids and gases, have higher energies because their atoms move more freely relative to the solid. But gases possess the highest energy.
3. The average kinetic energy of the molecules depend on the temperature. Generally, the higher the temperature, the greater kinetic energy.
4. A change in phase means the energy of the particles are also changed, as states in #2.
5. There are spaces between the molecules of matter. Otherwise, it will disobey the theory stated in #1.
6. There are attractive force between the molecules that depends on their distance between each other. Hence, the order of increasing attractive forces is gas < liquid < solid.
