Calculate the wavelength, in nanometers, of the spectral line produced when an electron in a hydrogen atom undergoes the transition from the energy level n = 2 to the level n = 1.

Answer 1

(1/wavelength) = R(1/1^2 - 1/2^2)
Look up R. That's the Rydberg constant. It's about 1.09 E7

Answer 2

Calculate the wavelength, in nanometers, of the spectral line produced when an electron in a hydrogen atom undergoes the transition from the energy level n = 5 to the level n = 1.