The Energy Change for an Electronic Transition in a One-Electron $\left(-2.178 \times 10^{-18} \mathrm{~J}\right) Z^{2}\left(\frac{1}{n_{\text {final }} 2}-\frac{1}{n_{\text {initial }} 2}\right)$

Multiple Choice

The energy change for an electronic transition in a one-electron atom or ion H, He⁺, Li²⁺, etc.) from n _initial to n _final Is given by , $\left(-2.178 \times 10^{-18} \mathrm{~J}\right) Z^{2}\left(\frac{1}{n_{\text {final }} 2}-\frac{1}{n_{\text {initial }} 2}\right)$
where Z is the atomic number.
Which one of the following species will have the longest wavelength emission line for the transition between the n_initial = 2 and n_final = 1 levels?

A) H
B) He⁺
C) Li²⁺
D) Be³⁺
E) B⁴⁺