Max Plank’s postulates of electromagnetic radiation are the following.
i)Radiation is non-continuous and made up of small discreet units of energy called ‘Quanta’.
Light quanta are ‘Photons’
ii) Quanta of same electromagnetic radiation are same and have same energy.
iii) Energy of the photon is proportional to the frequency of the radiation. E α ν = hν.
The equation, E = hν is the Plank’s Law.
The proportionality constant ‘h’ in the Planks’ Law is Plank’s constant and has a value of
h = 6.626×10-34with units of Js.
iv) Total energy or intensity of the radiation emitted is an integral multiple of this basic unit. E= nhν
v) Change of frequency changes the energy of the radiation but no relation with intensity.