10: Nuclear Physics and Radioactivity Last updated Jun 23, 2019 Save as PDF 9.5: Multielectron Atoms 10.1: The Nucleus Page ID17141 ( \newcommand{\kernel}{\mathrm{null}\,}\) Topic hierarchy10.1: The NucleusNuclear size is defined by nuclear radius; nuclear density can be calculated from nuclear size.10.2: RadioactivityDetectable amounts of radioactive material occurs naturally in soil, rocks, water, air, and vegetation.10.3: Quantum Tunneling and Conservation LawsIf an object lacks enough energy to pass through a barrier, it is possible for it to “tunnel” through imaginary space to the other side.10.4: Applications of Nuclear PhysicsRadiation therapy uses ionizing radiation to treat conditions such as hyperthyroidism, cancer, and blood disorders.