Q. Explain Kinetic Molecular Theory?
Ans.
The Kinetic Molecular Theory can be used to explain the properties of liquids and solids, as well as gases. As the following diagram illustrates, the molecular arrangements of solids, liquids, and gases vary considerably:
In liquids, molecules are much closer to each other than they are in gases. According to the Kinetic Molecular Theory, the forces of attraction between liquid molecules are much greater than those between gas molecules. Therefore, liquids have a definite volume even though they do not maintain a specific shape.
Liquids tend to be incompressible. The strength of the forces of attraction between liquid molecules varies from liquid to liquid. For example, water molecules tend to have a strong attraction for one another. On the other hand, some alcohol molecules tend to have a weak attraction for one another. Many alcohols are therefore volatile (i.e., they evaporate easily).
In solids, molecules are not only close together but are also held in a fixed position. Most solids have a definite internal structure called a crystal structure. This inner structure gives solids definite shapes as well as volume.