What determines the trend in ionization energy as you move DOWN a column on the periodic table.

Elements have a larger radius, electrons are pulled tightly, and have a higher ionization energy.

Elements have a smaller radius, electrons are pulled tightly, and have a higher ionization energy.

Elements have more energy levels, cannot pull in the electrons tightly, and have a lower ionization energy.

Elements have fewer energy levels, pull in the electrons weakly, and have lower ionization energy.

Elements have more energy levels, pull in the electrons tightly, and have a lower ionization energy.

Elements have fewer energy levels, pull the electrons tightly, and have a higher ionization energy.