The state with an excitation energy of 10.2 eV, is n= The transition energy is then ???E = (13.6 eV)(1/22 ??? 1/42 ) = 2.55 eV. E47-23 According to electrostatics and uniform circular motion, mv 2 /r = e2 /4?? 0 r2 , or v= The de Broglie wavelength is then ??= The ratio of ??/r is ?? 2 0 hn = = kn, r me2 a0 n2 where k is a constant.