Max Plank in 1901 , gave a new revolutionary theory known as Quantum theory of radiation.
Main features of this theory are :
E=hv where h is known as planks constant. h= 6.63x10-34 Js
- radiant energy is not emitted or absorbed continously but discontinously in the form of small packets of energy called Quanta. Each quanta is associated with a definite amount of energy .
- E is directly proportional to frequency of light,
3. The total amount of energy emitted or absorbed by the body will be some whole no. multiple of quantum ,i.e,
E=nhv , where n is an integer such as 1, 2, 3, ....
Since, the frequency , wavelength ?, and speed of light c are related by ?? = c, the Planck relation for a photon can also be expressed as
The above equation leads to another relationship involving the Planck constant.