Question

In Bohr’s theory of hydrogen atom, calculate the energy of the photon emitted during a transition of the electron from the first excited state to the ground state. Write in which region of the electromagnetic spectrum this transition lies.

Answer 1

The energy levels of hydrogen atom are given by

E_n (= -Rhc/n²) = -13.6/n² eV

For ground state n = 1

E₁ = –13.6 eV

For first excited state (n = 2)

E₂ = -13.6/4 = 3.4eV

∴ Energy of photon emitted

hv = E₂ – E₁ = –3.4 – (–13.6) eV = 10.2 eV

As transition from higher state to n = 1 correspond to Lyman series so the corresponding transition belongs to Lyman series.