The energy levels of an hydrogen atom are shown below. The transition corresponding to emission of shortest wavelength is

Step-by-step solution

Wavelength of photons released during de-excitation is given by, 1 λ = R 1 n 1 2 - 1 n 2 2 . Clearly, shortest wavelength will correspond to highest energy difference in de-excitation, which in the given figure will correspond to transition from n = 3 to n = 1 .