Question

1. explain the trend that both atomic radius and ionic radius increase going down a group in the periodic table.

Explanation:

As you move down a group in the periodic table, the number of electron - shells increases. Each new shell is farther from the nucleus. The outermost electrons are in higher energy levels and are less tightly held by the nucleus due to the shielding effect of the inner - shell electrons. This results in both the atomic and ionic radii increasing.

Answer:

As you move down a group, the number of electron - shells increases, leading to a greater distance between the outermost electrons and the nucleus, and the shielding effect of inner - shell electrons reduces the effective nuclear charge on the outermost electrons, causing both atomic and ionic radii to increase.