Question

When an electron in a hydrogen atom jumps from the third orbit to the second orbit, it emits a photon of wavelength 'λ'. When it jumps from the fourth orbit to third orbit, the wavelength emitted by the photon will be ______.

Options

• `20/7lambda`

• `16/25lambda`

• `20/13lambda`

• `9/16lambda`

Answer 1

When an electron in a hydrogen atom jumps from the third orbit to the second orbit, it emits a photon of wavelength 'λ'. When it jumps from the fourth orbit to third orbit, the wavelength emitted by the photon will be `underline(20/7lambda)`.

Explanation:

`1/lambda=R(1/2^2-1/3^2)=R(1/4-1/9)=(Rxx5)/36`

`1/lambda^'=R(1/3^2-1/4^2)=R(1/9-1/16)=Rxx7/144`

`lambda^'/lambda=5/36xx144/7=20/7`

`thereforelambda^'=20/7lambda`