Answer: Atomic weight increases from top to bottom and the number of shells increases from top to bottom
Explanation: As we go down the group that is vertical column, atomic weight increases as atomic number is increasing.
Moreover the number of electrons in the outershell does not increases but the number of shells increases from top to bottom as atomic number are increasing and electrons are increasing thus more number of shells are needed to fill these electrons.
Physical Properties doesnot remain identical as they do changes on going down the groiup.