| − | The electrons that exist furthest from an atom's nucleus. They are generally the electrons with the highest energy level number.<ref>Wile, Dr. Jay L. ''Exploring Creation With Chemistry''. Apologia Educational Ministries, Inc. 1998</ref> | + | The electrons that exist closest to an atom's nucleus. They are generally the electrons with the highest energy level number.<ref>Wile, Dr. Jay L. ''Exploring Creation With Chemistry''. Apologia Educational Ministries, Inc. 1998</ref> |