Spectral line series, any of the related sequences of wavelengths characterizing the light and other electromagnetic radiation emitted by energized atoms. The simplest of these series are produced by hydrogen. Hydrogen spectrum is an example of line emission spectrum or atomic emission spectrum. When an electric discharge is passed through hydrogen gas at low pressure, a bluish light is emitted. This light shows discontinuous line spectrum of several isolated sharp lines through prism. All these lines of H-spectrum have following six series: Lyman, Balmer, Paschen, Brackett, Pfund and Humphrey. To evaluate wavelength of various H-lines it was introduced the following expression: 1/λ = ν = RH [1/n12 - 1/n22)] The wavelength of marginal line = n12 / RH for all series. The infinity level (n = ∞) represents the highest possible energy an electron can have as a part of a hydrogen atom. So what happens if the electron exceeds that energy by even the tiniest bit? The electron is no longer a part of the atom. The infinity level represents the point at which ionization of the atom occurs to form a positively charged ion.