The diagram shows different transitions across the energy levels for an electron in a certain atom. Among these, which transition represents the emission of a photon with the most energy?

Step-by-step solution

Since, energy, E=13.6 Z^2 ( 1 n_f^2 - 1 n_i^2 ) where, Z is atomic number and n is orbital number. From given diagram, aligned & E_ I =13.6 Z^2 ( 1 3^2 - 1 1 )=-13.6 Z^2(0.88) & E_ II =13.6 Z^2 ( 1 3^2 - 1 4^2 )=13.6 Z^2(0.049) & E_ III =13.6 Z^2 ( 1 1^2 - 1 2 )=13.6 Z^2(0.75) & E_ IV =13.6 Z^2 ( 1 2^2 - 1 4^2 )=13.6 Z^2(0.187) aligned Here, E_ III is highest.