What happens to the size of the metal ions as you go down group I? Why?

Question

What happens to the size of the metal ions as you go down group I? Why?

Answer 1

This applies for all groups.
The general trend for atoms as you move down a group is for the size of the atoms to increase.
This is partially accounted for by the shielding of outer electrons by inner electrons. Also because atoms further down a group have more energy levels creating more distance between the nucleus and valence electrons.

Answer 2

the diameter of the atomic increases accordingly, thus the size is bigger