Question

Use the Rydberg formula for atomic hydrogen to calculate the
wavelength for the transition from n = 4 to n = 2. (b) What is
the name given to the spectroscopic series to which this transition
belongs? (c) Use Table 1.1 to determine the region of the spectrum
in which the transition takes place. If the change takes place in the
visible region of the spectrum, what color will be emitted?

Answer 1

(a) Rydberg equation: 1/λ = R(1/n₁² - 1/n₂²)

where λ is wavelength, R is Rydberg constant, n₁ and n² are the quantum numbers of the energy levels.

1/λ = 1.097 x 10⁷ x (1/2² - 1/4²) = 2056875 m^-1

Wavelength λ = 1/2056875

= 4.86 x 10^-7 m = 486 nm

(b) The name of the spectroscopic series with transitions ending at n = 2 is called:

The Balmer series.

(c) The region of the spectrum is visible light/visible region of the electromagnetic spectrum, which has wavelengths between390-750 nm.

The color corresponding to a wavelength of 486 nm is Cyan.