This lecture covers the advanced concepts of general chemistry, focusing on the 3D particle in a box, degeneracy, and quantum numbers. It delves into the electron structure of atoms, including the Schrödinger equation, atomic orbitals, and energy levels. The discussion extends to the hydrogen atom, its wave functions, and the separation of variables in the Schrödinger equation, emphasizing the importance of spherical coordinates. The lecture concludes with a detailed exploration of the hydrogen atom's electron wave functions, requiring three quantum numbers for characterization.