This lecture covers the Schrödinger equation in quantum mechanics, focusing on the probabilistic interpretation, unitarity, and conservation of probability. It explains the semi-implicit numerical scheme, the properties of the Crank-Nicolson scheme, and the observables in quantum mechanics. The lecture also discusses the Heisenberg uncertainty principle, Fourier transforms, and the importance of Hermitian operators. The conservation of probability and the implications of different numerical schemes are explored in detail.