Question

In Balmer series of hydrogen atom an excited hydrogen electron in an orbit higher than n=2 returns to the orbit n=2. But why does an hydrogen electron return to n=2 instead of n=1 as hydrogen electron will be stable in the first orbit ? (n is the principal quantum number).

Answer 1

Hydrogen spectrum corresponds the energy of light emitted due to transition of electrons. When electron comes to higher orbit to n=2 , wavelength of light corresponds to balmer series. However, electron's energy in second orbit is -3.5eV. To come into first orbit, electron has to release more energy to -13.5eV for being at first orbit. And Yes, electron will come to first orbit to get stabilised.