This lecture note covers the following topics: emission and absorption of
light, spectral lines, Atomic orders of magnitude, Basic structure of atoms, The
Central Field Approximation, Many-electron atoms, Energy levels, Corrections to
the Central Field, Spin-Orbit interaction, The Vector Model, Two-electron atoms,
Symmetry and indistinguishability, Nuclear effects on energy levels, Isotope
effects, Atoms in magnetic fields.