Answer:
The properties that increase down a column in the periodic table is
Ionic radii
Step-by-step explanation:
In periodic table column is also referred to as group.
Ionic radii tend to increase as you move from top to bottom of the group. This is because down the group there is increase of extra shell which increases the distance from the nucleus to outer shell.
The ionization energy and effective nuclear charge decreases down the group while number of valence shell electrons remain the same.