Q. Explain  heat according to kinetic theory of matter?

Ans. On an atomic level the definitions of heat and temperature becomes more precise. According to the kinetic theory of matter, the temperature of an object is proportional to the average kinetic energy of the molecules in the substance. In other words, fast moving molecules means the object will have a high temperature. Slow-moving molecules means a lower temperature.

The kinetic theory of matter proposes that heat is a measure of the total internal kinetic energy (microscopic jiggles) of the molecules and atoms making up the substance. In other words, since heat refers to the total kinetic energy in the whole substance, if we have a lot of the substance at a certain temperature there will be more heat, if we have only a little at the same temperature then there is less heat.

If, when I touch a hot stove, my hand is burned (heat was transferred to my hand), then I can deduce that the temperature (and kinetic energy of the molecules or atoms) of the stove was higher than the temperature (and kinetic energy of the molecules or atoms) of my hand. Temperature indicates when heat will be transferred but does not tell the whole story as to how much heat energy is stored in a substance.

Please note: Matter does not contain heat. Heat is energy that can be transferred.