Lyman, Balmer, Paschen, Brackett and Pfund series arise when electrons fall to levels n=1 to 5.
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The hydrogen spectrum consists of series of lines named after the lower energy level to which the electron falls. The Lyman series ends at n = 1 and lies in the ultraviolet, and the Balmer series ends at n = 2 and lies in the visible. The Paschen, Brackett and Pfund series end at n = 3, 4 and 5 and lie in the infrared. As the upper level n increases, the lines in each series crowd together and converge toward a series limit, which corresponds to ionisation of the atom. The positions of these lines are predicted exactly by the Rydberg formula.
Key ideas: Series are labeled by the final level n1: Lyman (n1 = 1, UV), Balmer (n1 = 2, visible, 656 nm H-alpha red, 486 blue-green), Paschen (3, IR), Brackett (4, IR), Pfund (5, IR). Within a series the lines converge towards a series limit at n2 = infinity. Lyman has the highest energy, with the first line at 121.6 nm.
Common mistakes and connections: Students reverse the series with the region, or think each series involves only one line. The Balmer series is the only one mostly in the visible. Remember that transitions end on n1 and start from higher n2. Use the Rydberg formula to compute any line, and the Bohr model to explain them.
Lyman lines end on n=1 in the ultraviolet, while Balmer lines end on n=2 and fall in the visible region. The interactive lesson shows this as a live animation or chart.
The red H-alpha line at 656 nm is the transition from n = 3 to n = 2 in the Balmer series.
Lyman, Balmer, Paschen, Brackett and Pfund series arise when electrons fall to levels n=1 to 5.
Hydrogen Spectrum Series is a intermediate topic in Atomic Structure & Periodicity. It builds on the vocabulary of beginner topics in this area.
Study these earlier topics in Atomic Structure & Periodicity first: Photon, Atomic Emission Spectra, Atomic Absorption Spectra.
The next topics in Atomic Structure & Periodicity are Rydberg Equation and Bohr Model.
Yes. The interactive lesson includes a self-check question on Hydrogen Spectrum Series, and the Atomic Structure & Periodicity quiz draws on every topic in this area.
Hydrogen Spectrum Series is topic 43 of 115 in Atomic Structure & Periodicity.