Question

Suppose an electron in some atom absorbs energy and transitions from level 1 up to level 4. Which of the following is a true statement regarding the electron transitions back down to level 1?

a. It must transition from 4 to 3, then 3 to 2, then 2 to 1. All downward transitions are one step at a time.
b. 4 to 2, followed by 2 to 1, is possible. Downward transitions can be any number of levels.
c. It can go from 4 to 1 only. The downward transition must match the upward one.

Answer 1

b. 4 to 2, followed by 2 to 1, is possible. Downward transitions can be any number of levels.

Downward transitions can indeed be any number of levels at a time. Together with the rule that each downward transition produces a photon of a particular color, you can see why each element has a unique the emission spectrum.