The book "Volume 3. Quantum mechanics" is a fascinating journey into the world of microscopic particles, where gravity no longer acts, but other forces do, which allow us to understand the nature of the smallest objects in the universe. In this book, the author examines in detail the basic concepts and principles of quantum mechanics, revealing to the reader the incredible world of quantum effects, interference, superposition and quantum information. The reader will be able to learn about the amazing phenomena of quantum tunneling, exotic quantum states of matter, as well as about quantum coding and quantum computing. The author explains the complex concepts of quantum mechanics in a clear and accessible way, providing the reader with the opportunity to deepen their knowledge in this fascinating field of physics. The book "Volume 3. Quantum Mechanics" will be a useful guide for students of physics and mathematics majors, teachers, scientists and everyone who is interested in the fundamental principles of quantum physics and its applications in the modern world.