Question

Recall that an emission transition involves a jump from an upper energy level down to a lower energy level. With this in mind, what quantum number do lines of the Lyman series have in common? The Balmer series? The Paschen series? How can we designate a set of lines as a “series”?

Answer 1

Lyman series are the set of transition found in hydrogen spectrum having a transition from higher energy levels n>2or=2 to n=1 where n is the principal quantum number. All the transitions have a common principal quantum number n=1 I,e the ground state of the transitions are common.

Similarly Balmer series are set of transitions from higher energy levels n> or = to 3 to n=2 , here also the principal quantum number of ground state of transitions is common I,e n=2

Paschen series transitions from higher energy levels n =or> 4 to n=3, here also the ground state principal quantum number is common for all the transitions I,e n=3

A set of lines said to be a series when they have a common ground state or an excited state I e either the principal quantum number should be same. Ex: Lyman series: no. Of transitions occur from n=2,3,4,5.... To n=1, since the ground state principal quantum is common for all the transitions, the lines appearing due to these transitions are grouped in as a series and named after the scientist as Lyman series.