Question

Why large no. of lines appear in the spectrum of hydrogen although it contains only one electron?

Answer 1

Although hydrogen has only one electron, it contains many energy levels. When its electron jumps from higher energy level to a lower one, it releases a photon. Those photons cause different colours of light of different wavelengths due to the different levels. Those photons appear as lines. For this reason, though hydrogen has only one electron, more than one emission line is observed in its spectrum.

So of the energy changes are as shown below: Wavelength Transition Color (nm) --------------------------------------------- 383.5384 9 -> 2 Ultra Violet 388.9049 8 -> 2 Ultra Violet 397.0072 7 -> 2 Ultra Violet 410.174 6 -> 2 Violet 434.047 5 -> 2 Violet 486.133 4 -> 2 Bluegreen (cyan) 656.272 3 -> 2 Red 656.2852 3 -> 2 Red