PHYWE Atomic spectra of two-electron systems: He, Hg

Principle The spectral lines of He and Hg are investigated using a diffraction grating. The wavelengths of the lines are determined by the geometrical arrangement and the constants of the diffraction grating. Advantages The spectral lines of different elements can be determined with high accuracy Simple setup for high-level experiments High-voltage power supply with high safety standards ensures safe experiments Objectives Determination of the wavelengths of the most intense spectral lines of He. Determination of the wavelengths of the most intense spectral lines of Hg. Learning Objectives Parahelium Orthohelium Exchange energy Spin Angular momentum Spin-orbit interaction Singlet and triplet series Multiplicity Rydberg series Selection rules Forbidden transition Metastable state Energy level Excitation energy