The popular introductory course in theoretical physics covers all essential areas for Bachelor's, Master's, or Diploma studies across seven volumes. Each volume thoughtfully provides the necessary theoretical and physical knowledge required for the respective semester. Numerous exercises with detailed solutions serve to deepen the understanding of the material. The second part of the fifth volume deals with applications and the expansion of the concepts of quantum mechanics developed in the first part. This new edition includes several new problems, has been thoroughly revised, and is supplemented by additional chapters on scattering theory. The use of a two-color presentation allows for a very clear and quick access to the course content.