The Kinetic Theory of Matter postulates that matter is made up of tiny particles that are continuously in motion and so possess kinetic energy . It is also known as the Molecular Theory. The particles may be atoms, molecules or ions. Recall that matter exists in three common states, namely solid, liquid and gaseous states; although, we also have plasma and Einstein-Bosé condensate as additional states of matter. However, these are beyond our scope of discussion. The major differences in the properties of solid, liquid and gas are the degrees of intermolecular forces of attraction and average kinetic energy of the particles. While the intermolecular force is strongest in the solid state, which confers upon a solid its rigidity in shape and form, it is weakest in the gaseous state, which explains why a gas is formless and takes the shape and volume of the containing vessel. The intermolecular force of attraction is however, mild (not very strong and not very weak) in the liquid sta...
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