Which of the spectral lines of the Brackett series is closest in wavelength to the first spectral ine of the Paschen series? By how much do the wavelengths differ? Know: The first line of the Paschen series occurs at 18,751.1A with an energy of En=-13.6/(3)2. I know the answer is n=9 with a sepperation of 577A but I'm super confused how they arrived at this answer. If anyone could help at least to explain what is esentially going on here, or point me in the right direction it would be much appreciated!!! Thanks!