Question

Obtain an expression for the frequency of radiation emitted when a hydrogen atom de-excites from level n to level (n-1). For large n, show that this frequency equals the classical frequency of revolution of the electron in the orbit.

Answer 1

When a hydrogen atom de-excites from level n₁ to n_p the frequency of radiation emitted is given by

When n is large, 2n - 1 ≈ 2n and (n - 1)² ≈ D²

∴ The above equation becomes

classically, frequency of revolution of electron is given by,

Hence, when n is large, the frequency of radiation emitted is equal to the classical frequency of revolution of the electron in the orbit.