<P> H - alpha (Hα) is a specific deep - red visible spectral line in the Balmer series with a wavelength of 656.28 nm in air; it occurs when a hydrogen electron falls from its third to second lowest energy level . H - alpha light is important to astronomers as it is emitted by many emission nebulae and can be used to observe features in the Sun's atmosphere, including solar prominences and the chromosphere . </P> <P> According to the Bohr model of the atom, electrons exist in quantized energy levels surrounding the atom's nucleus . These energy levels are described by the principal quantum number n = 1, 2, 3,...Electrons may only exist in these states, and may only transit between these states . </P>

When is h alpha line in the emission spectrum of hydrogen atom obtained