Question

how atomic size changes from top to bottom in a group​

Answer 1

Answer:The atomic radius of atoms generally increases from top to bottom within a group. As the atomic number increases down a group, there is again an increase in the positive nuclear charge. ... As the atomic number increases within a period, the atomic radius decreases.

Answer 2

Answer;- While moving

from top to the bottom of a group, there is an increase in

number of shells succeeding which increases the distance

between nucleus and valence shell.  Thus, the atomic size increases while moving top to bottom in group.