The momentum of a photon having energy (hv) is given by the elation:
(i)
Where,
wavelength of the electromagnetic radiation
speed of light
Planck’s constant
De Broglie wavelength of the photon is given by the relation:
But,
Therefore, (ii)
Where, mass of the photon
velocity of the photon
The wavelength of electromagnetic radiation and the de Broglie wavelength of the photon are same, according to equations (i) and (ii).