Question

Which of the hydrogen spectrum series is in the visible region ?

• A. Lyman series
• B. Balmer series
• C. Bracket series
• D. Pfund series

Answer 1

Answer:

B. Balmer series

• The Balmer series is the only set of emission lines in the hydrogen spectrum that falls within the visible light region.

• It occurs when an electron transitions from a higher energy level (n > 2) to the second energy level (n = 2).

• The lines in the Balmer series correspond to wavelengths ranging approximately from 380 nm to 750 nm.

• The series was discovered by Johann Balmer in 1885, and his empirical formula was later derived theoretically by Niels Bohr.

• The various series of the hydrogen spectrum and their respective regions are:

  • Lyman series: Ultraviolet (n=1)

  • Balmer series: Visible (n=2)

  • Paschen series: Infrared (n=3)

  • Brackett series: Infrared (n=4)

  • Pfund series: Infrared (n=5)

• The general formula for the wavelength λ of these lines is given by the Rydberg formula: 1/λ = R_H * (1/n_1^2 - 1/n_2^2), where R_H is the Rydberg constant.