According to Bohr's theory, what is the frequency of the light emitted by an electron in a transition from the first excited state to the ground state in hydrogen? Compare this with the frequency of the orbital motion of the electron in the first excited state.

Respuesta :

Answer:

 frequency  transition  2.4626  10¹⁵ Hz

Explanation:

Bohr's atomic model works very well for the hydrogen atom, the energy of the states is described by the expression

 

              En = - 13.606 /n² eV

Where n is a positive integer

Let's calculate the energy for the base state   n = 1     E1 = -13.606 eV

The energy for the first excited state        n = 2     E2 = -13.6060 / 2²

                           E2 = -3.4015 Ev

The variation of the energy for the transition is

           ΔE = E2 -E1

           ΔE= -3.4015 +13.606

           ΔE = 10.2045 eV

We use the Planck equation to find the frequency

            E = 10.2045 eV (1.6 10⁻¹⁹ J/1 eV) =  16.3272 10⁻¹⁹ J

            E = h f

            f = E / h

            f = 16.3272 10⁻¹⁹ / 6.63 10⁻³⁴

            f = 2.4626  10¹⁵ Hz

Let's calculate the frequency of the excited state

             E2 = 3.4015 eV (1.6 10⁻¹⁹ J/1eV) = 5.4424 10⁻¹⁹ J

             f = 5.4424 10⁻¹⁹ / 6.63 10⁻³⁴

             f = 0.8209 10¹⁵ Hz

To make the comparison, divide the two frequencies

             f transition / f excited = 2.4626 / 0.8209

             f transition / f excited = 3

The frequency of the transition is 3 times greater than the frequency of the first excited state