The nucleus is a collection of neutrons and protons, what else is there to know? Well, perhaps surprisingly, we still do not have a detailed description of the force that binds the nucleus, and we still don't know how the nature and properties of the quarks and gluons within the nucleons influence their interactions. Fundamental questions you might think, and indeed this remains one of the major areas of research in Nuclear Physics. In this module you will discover what we do know about the details of the nuclear force, the strong interaction, and the models which presently employ this force to calculate the properties of light nuclei. This approach cannot yet be extended to heavier nuclei and mean-field theories are required, a particular focus will be the nuclear shell model; the evidence for nuclear shells and the predictive capability of the shell model. The module will use the vehicle of three classes of decay to examine the theory and experimental manifestations of the strong, weak and electromagnetic forces within the nucleus, namely alpha, beta and gamma decay. These processes will also be used to illustrate present areas of contemporary nuclear physics research.