Q: What are the widths of the wavelength intervals over which (a) the Lyman series and (b) the Balmer series extend? (Each width begins at the longest wavelength and ends at the series limit.) (c) What are the widths of the corresponding frequency intervals? Express the frequency intervals in tetrahertz (1THz = 10^12 Hz). Dont understand what to do - and dont really understand Balmer and Lyman Series either - Any help with this question would be appreciated - thankyou!