Using the Bohr model, find the wavelength in nanometers of the radiation emitted by a hydrogen atom, when it makes a transition from the n = 9 state to the n = 1 state.

Respuesta :

Answer:

[tex]\lambda_{H} = 92.5 nm[/tex]

Given:

n = 9

n' = 1

Solution:

In Bohr's Model, the radiation emitted by a hydrogen atom on transition from the energy level, n = 9 to n' = 1 is given by:

[tex]\Delta E_{H} = 13.6[\frac{1}{n^{2}} - \frac{1}{n'^{2}}][/tex]               (1)

Also,

[tex]\Delta E_{H} = \frac{hc}{\lambda_{H}}[/tex]

where

h= Planck's constant

c = speed of light

[tex]\lambda_{H}[/tex] = wavelength of radiation emitted by hydrogen atom

Therefore, eqn (1) becomes:

[tex]\frac{hc}{\lambda_{H}} = 13.6[\frac{1}{n^{2}} - \frac{1}{n'^{2}}][/tex]

[tex] \frac{6.626\times 10^{- 34}\times 3\times 10^{8}}{\lambda_{H}} = 13.6[\frac{1}{9^{2}} - \frac{1}{1^{2}}][/tex]

[tex]\frac{1.988\times 10^{- 25}}{\lambda_{H}} = 13.6\times 0.988\times 1.6\times 10^{- 19}[/tex]

(since, 1 eV = [tex]1.6\times 10^{- 19}[/tex])

[tex]\frac{1.988\times 10^{- 25}}{\lambda_{H}} = 2.14\times 10^{- 18}[/tex]

[tex]\lambda_{H} = 9.25\times 10^{-8} m = 92.5 nm[/tex]