Relativistic corrections become necessary when the expression for the kinetic energy becomes comparable with mc2, where m is the mass of the particle. At what de Broglie wavelength will relativistic corrections become important for an electron?
We know the de Broglie wavelength is given by,
where h is the Planck’s constant, m is the mass and v is the velocity
(a) When, λ =10nm
(b) When, λ =10–1nm
(c) When, λ =10–4nm
(d) When, λ =10–6nm
Hence, in cases (c) and (d) velocities are greater than the speed of light and hence relativistic corrections will become important for an electron.