A simple clear answer plz, Thanks. Why when going down a group of the periodic table, electrons are also being added but the sizes of the atoms increase?

The number of energy levels increases as you move down a group as the number of electrons increases. Each subsequent energy level is further from the nucleus than the last. Therefore, the atomic radius increases as the group and energy levels increase. Hope this helps!

Explanation:

um same as the answer...?

1.43 x 10^-11 j the guy commented the awnser just making sure u see it .