If each hydrogen atom in the ground state, 1.0 inole of H atoms are excited by absrobing photons of energy 8.4 eV, 12.09 eV and 15.0 eV of energy, then the number of spectral lines emitted is equal to

Answer

9

Explanation

By absorbing 8.4 ev not excited
By absorbing 15eV , it is ionised . So, only possible is 12.09eV.
`Delta E =-13.6 + 12.09 =-1.5 eV`
i.e. , n=3