Which of the following electron jump in a hydrogen atom absorbs the photon of highest frequency?

Question

A. n = 1 to n=2

B. n = 2 to n=1

C. n = 2 to n=3

D. n = 3 to n=2

Answer 1

As n increases, the spacing between energy levels becomes smaller and smaller (it's proportional to 1/n^2 - 1/(n+1)^2). Hence, the largest jump is from n = 1 to n = 2. Since the hydrogen atom has to absorb a photon, the change must require energy - meaning the electron was excited from n = 1 to n = 2. If the electron fell from n = 2 to n = 1, it would have emitted a photon.