Question

define atomic radius . how does it vary down a group and along a period​

Answer 1

Explanation:

distance distance between nucleus and outermost shell of an atom is called as a atomic radius of that atom

the the atomic radius vary down a group because when we go down a group the new shell is added

when we go along a group the cell number does not change in the same shell electron gets added to atomic radius decreases due to addition of electron

in short

it increases down a group

it decreses along a period