MCQ Detailed View

The Kinetic Molecular Theory (KMT) is the theory that explains the behavior of matter in terms of the motion of its particles. According to this theory, all matter is made up of tiny particles such as atoms, molecules, or ions, and these particles are in constant motion. The speed and nature of this motion depend on the state of matter and the temperature.

In solids, the particles are closely packed and vibrate in fixed positions, which is why solids maintain a definite shape. In liquids, particles have more freedom of movement; they slide past one another, which allows liquids to flow while still maintaining a definite volume. In gases, the particles move very rapidly in straight-line paths until they collide with each other or the walls of the container. This random, continuous, and straight-line motion of gas particles explains many gas properties such as pressure, diffusion, and expansion.

The theory also assumes that collisions between gas particles are elastic, meaning there is no loss of total kinetic energy. Temperature is directly related to the average kinetic energy of the particles; higher temperature means faster motion of particles.

Other options in the question represent different theories. Bohr’s Theory explains the structure of the atom and energy levels of electrons, not particle motion in general. Dalton’s Atomic Theory describes the nature of atoms and elements but does not explain how particles move.

Therefore, the theory specifically describing the motion and behavior of particles of matter is the Kinetic Molecular Theory. It provides the foundation for understanding the properties of gases and is one of the most important models in Physical Chemistry.