Principle
The spectral lines of He and Hg are examined by means of a diffraction grating. The wavelengths of the lines are determined from the geometrical arrangement and the diffraction grating constants.
Tasks



Determination of the wavelengths of the most intense spectral lines of He.
Determination of the wavelengths of the most intense spectral lines of Hg.



What you can learn about

Parahelium
Orthohelium
Exchange energy
Spin
Angular momentum
Spinorbit interaction
Singlet and triplet series
Multiplicity
Rydberg series
Selection rules
Forbidden transition
Metastable state
Energy level
Excitation energy