The fifth volume of the physics course, widely known in our country and abroad The book is written on the basis of lectures, which for a number of years were read by the author to students of the Moscow Institute of Physics and Technology .. The main attention is paid to clarifying the physical meaning and content of the basic laws and concepts of atomic and nuclear physics, establishing the boundaries of the applicability of these laws, developing students' skills in physical thinking and the ability to set and solve specific tasks. For students of physical and mathematical faculties of universities, physico-technical and engineering-physical institutes, as well as universities where physics is the main discipline