the branch of physics (the science of relationships between matter and energy) which deals with atoms, their nuclear structure and the behavior of nuclear particles. Nuclear means pertaining to the nucleus or central core of an atom. —HEV Approved Glossary, —NED Approved Glossary, —State of ManCongress Approved Gls (14.5.92), —PDC Volume 1 Approved Glossary, —PDC 2 Approved Glossary, —PDC Volume 3 Approved Glossary, —PDC Volume 4 Approved Glossary, —PDC Volume 7 Approved Glossary, —PDC Volume 8 Approved Glossary