Question

In Davisson-Germer experiment an electron beam of energy 60 eV falls normally on the surface of a crystal. If the maximum intensity is obtained at an angle of 60° to the direction of incident beam, then the inter-atomic distance in the lattice plane of the crystal will be

Answer 1

Given :

Energy of electron beam = 60eV

Angle at which maximum intensity is obtained = 60°

To Find :

The inner atomic distance in the lattice plane of the crystal will be

Solution :

• From Davisson - Germer experiment we have ,nλ = 2dsinθ

•    λ = 2dSinθ

•    h / √energy = 2dsinθ

•    12.27 / √60  = 2d×Sin 60°

•    1.584 = 2d×Sin 60°

•    d = 0.914 A°

The inneratomic distance in the lattice plane of the crystal will be 0.914 A°