# Electron transitions

#### Clyner82

The light source for an experiment is a discharge lamp containing excited atoms which emit light at several wavelengths. The three lowest energy levels of one of these atoms is n = 1, 2 and 3.

Electron transitions between these energy levels can produce three different wavelengths of radiation. The transition between n = 2 and n = 1 causes the 440 nm photons.

Photons at 590 nm are also emitted. Which transition causes these photons?

I tried using the 1/λ = R(1/λf^2 - 1/λi^2) but the wavelength doesn't agree?

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#### topsquark

Forum Staff
The light source for an experiment is a discharge lamp containing excited atoms which emit light at several wavelengths. The three lowest energy levels of one of these atoms is n = 1, 2 and 3.

Electron transitions between these energy levels can produce three different wavelengths of radiation. The transition between n = 2 and n = 1 causes the 440 nm photons.

Photons at 590 nm are also emitted. Which transition causes these photons?

I tried using the 1/λ = R(1/λf^2 - 1/λi^2) but the wavelength doesn't agree?
The Rydberg formula (in any setting that I've seen it) is
1/(lambda) = R ( 1/(n1)^2 - 1/(n2)^2 ), where n1 < n2.

Your first wavelength allows you to calculate R. Then there are two more possibilities: n1 = 1, n2 = 3; and n1 = 2, n2 = 3. The trouble is I can't replicate the 590 nm wavelength. Are you sure you have the wavelengths correct?

-Dan