This lecture delves into the quantum physics problem, focusing on a specific case: the Coulomb potential. The instructor explains the assumptions made to simplify the problem, leading to the quantification of energy levels and the stability of the hydrogen atom. The lecture covers the radial equation solution, energy quantization, and the classification of wave functions based on orbital angular momentum. It concludes with insights into the behavior of wave functions for different energy levels and the characteristic length scale of the hydrogen atom.