Generally, as you go down a group in the period ic table, what happens to atomic radius and IE?

Atomic radius increased from top to bottom in group with increase of atomic number. while ionization energy decreased.

Explanation:

Definition of atomic radii:

The atomic radius is the distance between center of two similar bonded atoms.

Ionization energy:

The amount of energy required to remove the outer most electron from gaseous atom.

Trend along group:

In group by addition of electron atomic radii increase from top to bottom due to increase in atomic number. As the atomic number increased one more electron is added and because of this electron on more electronic shell is added. Thus the outer most shell becomes further away from the nucleus and hold of nucleus becomes weaker. Although nuclear charge is also increased but at the same time atomic size also increased and addition of electrons create shielding effect, thus it is easy to remove the electron and in this way ionization energy decreased from to to bottom.

Trend along period:

As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases.