Question

Give scientific reason:
Atomic size decreases from left to right in the periods and increases down the group

Answer 1

Explanation:

because

when we go from left to right no new subshell is added .

when we go from up to Down then new subshell is added so shielding effect increases. so then nucleus attracts the inner subshell's electron but it can not attract the newly added subshell with so much power. so gradually size increases.

but when we go from left to right it does not occur.

hope it will help you.