Which of the following statements about kinetic theory of matter is not correct?

The statement "When a body is heated the average kinetic energy of its molecules decreases" is not correct in the context of kinetic theory of matter. According to the theory, when a body is heated, the average kinetic energy of its molecules increases because heat is the energy of molecular motion. Therefore, the correct option is (B). Explanation: The kinetic theory of matter explains the behavior of matter in terms of the motion of its constituent particles. The theory assumes that matter is made up of very tiny particles called molecules, which are always in motion. When a body is heated, the kinetic energy of its molecules increases, and the temperature of the body increases as a result. Similarly, when a body is cooled, the kinetic energy of its molecules decreases, and the temperature of the body decreases as a result. In addition, the theory explains that the molecules of a gas move more freely than those of a liquid because the intermolecular forces between gas molecules are weak. The molecules of a liquid move more freely than those of a solid, but less freely than those of a gas because the intermolecular forces in liquids are stronger than those in gases but weaker than those in solids. Therefore, option (C) is correct.