Question -
Answer -
Wavelength of an electron 
= 1 × 10−9 m
Planck’s constant, h = 6.63× 10−34 Js
(a) The momentum of anelementary particle is given by de Broglie relation:
It is clear that momentumdepends only on the wavelength of the particle. Since the wavelengths of anelectron and a photon are equal, both have an equal momentum.
(b) The energy of aphoton is given by the relation:
Where,
Speed of light, c = 3 × 108 m/s
Therefore, the energy ofthe photon is 1.243 keV.
(c) The kinetic energy (K)of an electron having momentum p,is given by the relation:
Where,
m = Mass of the electron = 9.1 × 10−31 kg
p = 6.63 × 10−25 kg m s−1
Hence,the kinetic energy of the electron is 1.51 eV.