Why does ionic size increase down a group?
The size of the atom before becoming an ion is larger as the atoms go down in a group or family.
For the group I A and II A for an example the losing of an electron causes the atom to be smaller than tthe neutral atom. While this is true of all the elements in these families, the starting points are different.
Li after losing an electron goes to
Na after losing an electron goes to
Because the second shell is larger than the first shell the
ion with be bigger than the
This is the same for all families because each element in the family is in a larger shell as the elements go down on the Periodic Table.