This module gives an introduction to nuclear physics. Starting from the bulk properties of atomic nuclei different modes of radioactivity are discussed including simple theoretical approaches to understanding decay rates, before a closer look at the nucleon-nucleon interaction leads to the development of the shell model. Collective models of the nucleus leading to a quantitative understanding of rotational and vibrational excitations are developed. Electromagnetic decays between excited states are introduced as spectroscopic tools to probe and understand nuclear structure, as well as various direct nuclear reactions and the associated experimental observables. Links are made throughout the module between the topics that overlap with particle physics and astrophysics. Finally, modern methods for producing and studying radioactive isotopes are evaluated, giving an overview of state-of-the-art research in the field of nuclear structure physics.