HW Question 1A.11

[Jessica Esparza 2H]

In the spectrum of atomic hydrogen, several lines are generally classified together as belonging to a series (for example, Balmer series, Lyman series, Paschen series), as shown in Figs. 1.10 and 2.1. What is common to the lines within a series that makes the grouping them together logical?

I am confused about how the solution manuals got their answer?
The solutions manual says: In each of these series, the principal quantum number for the lower energy level involved is the same for each absorption line. Thus for the Lyman series, the lower energy level is n=1; for the Balmer series, n=2; for Paschen, n=3; and for the Brackett, n=4.

[Michelle Song 1I]

Each series contains the transitions of an electron going from a higher energy to a specific lower energy level. For the Lyman series, the lower energy level is n = 1, for Balmer, the lower energy level is n = 2 and so on. So essentially, what is common to the lines within a series is that they end at the same energy level.

[Brandon Valafar]

This is because the different series have different steps of going from higher to lower energy levels, as the comment above me said.