Elements are arranged in groups by similar atomic structure on the periodic table. this allows for an element's properties to
be predicted based on general periodic trends. one of these trends, ionization energy, increases up a group and to the right along
a period and can be defined as the
a) energy required to add an electron
b) energy required to excite an electron
c) energy required to remove a core electron
d) energy to required to remove a valence electron