Carefull analysis of the experimental observatinos of the line spectrum emitted by hydrogen showed that it can be described in terms of empirical formulae. The hydrogen spectrum consists of the following series each named after it discoverer.
(1) The Lymann Series
R is a constant known as Rydberg’s constant. The series lies in the ultra–violet region.
(2) For the Balmer Series
The Balmer series lies in the visible part of spectrum. The line for transition from n = 3, 4, 5,....... to n = 2 are known as Hα ;Hβ and Hγ lines respectively.
(3) For the Paschen Series
The Paschen series lies in the infrared region.
(4) For the Brackett Series
The Brackett and the Pfund series lie in far infrared region.