An electron in sixth orbit of hydrogen atom deexcites to ground state in all possible ways. Number of spectral lines observed in Balmer series are

Number of spectral lines=nn+12   where n=n2-n1 Given, n=6-1=5 Number of spectral lines=55+12                                                 =15 Number of spectral lines in Balmer series=4; The possible electronic transitions are 6→2, 5→2, 4→2, 3→2