Nuclear Reactions explains the development of nuclear reactions, focusing on the study of the quantum scattering phenomena in terms of pure states. This book discusses the early applications of quantum mechanics; simple quantitative ideas; theory of Breit and Wigner; and statistical properties of resonances. The elastic scattering experiments and optical model fits; particle propagation in the optical model; and nuclear matter are also elaborated. This text likewise covers the shell model; inelastic scattering; and (p, 2p) reaction. This publication is beneficial to undergraduate students who have finished the first course in quantum mechanics, as well as those interested in the theory of nuclear reactions.