The Balmer series is the series of transitions and resulting emission lines of the hydrogen atom as an electron goes from n ≥ 3 to n = 2 (where n refers to the energy level of the electron). The transitions are named sequentially by Greek letter: n = 3 to n = 2 is called H-α, 4 to 2 is H-β, 5 to 2 is H-γ, etc. As the spectral lines associated with this series are located in the visible part of the electromagnetic spectrum, these lines are historically referred to as H-alpha, etc., rather than Balmer-alpha, etc.

Balmer's formula

where λ is the wavelength of the emitted light and R_H is the Rydberg constant for hydrogen. The Rydberg constant for an infinitely heavy nucleus is 10,973,731.534 m⁻¹.

See also

• Bohr model
• H-alpha
• Lyman series
• Paschen series
• Rydberg formula