The number of energy levels increases as you move down a group as the number of electrons increases
Step-by-step explanation:
The determination of distance of separation between the two nuclei of likely atoms connected together called atomic radius. This in a group usually increases from top to bottom. With the increase in the atomic number in the group, the positive nuclear charge increases again. However, the amount of principle energy is also increasing.
High principle energy levels made up of orbits of higher size than low energy levels. The impact of this exceeds the increased nuclear charge, and thus the atomic radius gets increased when going down a group in the periodic tables.
Atomic radius gradually decreases from the side left to the right during the elemental period. This is because all electrons of the same size are added over time or in a family of elements.