what are the assumptions of planck's quantum theory
Classical wave theory of radiations was not able to explain black body radiations photo-electric effect, etc. In order to explain these facts Planck (1901) gave a theory called Planck’s quantum theory of radiation.
Max Planck in 1901 studied the energy of radiations of different frequencies radiated from hot bodies, known as black bodies. On the basis of these studies, Planck postulated a theory known as Planck’s quantum theory of radiations.
The various postulates of quantum theory of radiations are as follows:
(i) A radiation has energy. As light and heat are radiations, they are also associated with energy.
(ii) Radiant energy is not emitted or absorbed continuously but discontinuously in the form of small packets called photons. Photon is not a material body but is considered to be a mass less packet of energy.
(iii) The energy E of a photon is related to the frequency of radiation, v; the two being related as E = h v, Where h is planck’s constant.
(iv) Whenever a body emits or absorbs energy, it does so in whole number multiples of photons, i.e., nhn where n = 1, 2, 3 and never 1.2, 2.5, 3.7 etc.
Classical wave theory of radiations was not able to explain black body radiations photo-electric effect, etc. In order to explain these facts Planck (1901) gave a theory called Planck’s quantum theory of radiation.
Max Planck in 1901 studied the energy of radiations of different frequencies radiated from hot bodies, known as black bodies. On the basis of these studies, Planck postulated a theory known as Planck’s quantum theory of radiations.
The various postulates of quantum theory of radiations are as follows:
(i) A radiation has energy. As light and heat are radiations, they are also associated with energy.
(ii) Radiant energy is not emitted or absorbed continuously but discontinuously in the form of small packets called photons. Photon is not a material body but is considered to be a mass less packet of energy.
(iii) The energy E of a photon is related to the frequency of radiation, v; the two being related as E = h v, Where h is planck’s constant.
(iv) Whenever a body emits or absorbs energy, it does so in whole number multiples of photons, i.e., nhn where n = 1, 2, 3 and never 1.2, 2.5, 3.7 etc.
