The wavelength of the Balmer series lies in the 

CONCEPT:

• Hydrogen Spectrum and Spectral series: When a hydrogen atom is excited, it returns to its normal unexcited (or ground state) state by emitting the energy it had absorbed earlier.
• This energy is given out by the atom in the form of radiations of different wavelengths as the electron jumps down from a higher to a lower orbit.
• The transition from different orbits causes different wavelengths, these constitute spectral series which are characteristic of the atom emitting them.
• When observed through a spectroscope, these radiations are imaged as sharp and straight vertical lines of a single color.
  
• Mainly there are five series and each series is named after it's discovered as Lyman series (n1 = 1), Balmer series (n1​ = 2), Paschen series (n1​ = 3), Bracket series (n1​ = 4), and Pfund series (n1​ = 5).
• According to Bohr's theory, the wavelength of the radiations emitted from the hydrogen atom is given by
  \(\frac{1}{\lambda } = RZ^2\left[ {\frac{1}{{n_1^2}} - \frac{1}{{n_2^2}}} \right]\)

where

n2 = outer orbit (electron jumps from this orbit),

n1 = inner orbit (electron falls in this orbit),

Z = atomic number

R = Rydberg's constant.

Lyman series is obtained in the ultraviolet region.

Balmer series is obtained in the visible region.

Paschen series is obtained in the Infrared region.

Brackett series is obtained in the Far infrared region.