Operators. Commuting and non-commuting observables. The Heisenberg uncertainty relations. Measurement in Quantum Mechanics. Collapse of the wave-function. Angular momentum - eigenvalues and eigenfunctions. Matrix representations of operators and wave functions. Stern-Gerlach experiment. Spin. Time-independent perturbation theory. Fine structure. The Zeeman effect. Identical particles, atoms and solids. Variational calculations. The helium atom. Finite basis set calculations.