From the nuclear atom to quantum states and lasers.
Thomson's, Lenard's and Rutherford's atomic models and alpha scattering, the hydrogen spectrum and Rydberg formula, why the classical nuclear atom fails, Bohr's postulates, orbit radii and energy levels, ionization and excitation energies, hydrogen-like ions, the wave-function picture and quantum numbers, spin, shells and the Pauli principle, and stimulated emission and the laser.