The change in energy of a one-electron atom or ion for an electronic transition from the initial energy level n_i to the final energy level n_f is given by Which of the following species will have the longest wavelength emission line for the transition between the n_i  2 and n_f  1 levels? A)H B)He ^ C)Li² ^ D)Be³ ^ E)B⁴ ^

Question

Quizplus · Accepted Answer

The energy change for the transition is given by the formula 11eaa952_9bcd_f584_ae90_75cfb6f82ff7_TB3835_11, which depends on the initial and final energy levels only. Therefore, the wavelength of the emitted radiation, which is inversely proportional to the energy change, will be the same for all species undergoing this transition. However, the energy levels of the hydrogen atom are uniquely given by En = -13.6/n^2 eV, where n is an integer, and the transition from n=2 to n=1 gives the famous "Lyman alpha" emission at 121.6 nm, which is the longest wavelength (lowest energy) line in the Lyman series. Therefore, the correct answer is A.

The Change in Energy of a One-Electron Atom or Ion