What happens to atomic radius as you move down a group in the periodic table?

As you move down a group in the periodic table, the atomic radius increases due to several factors associated with the structure of atoms. Each element in a group has an additional electron shell compared to the one above it. As you progress down the group, additional energy levels are added, which means that the distance between the nucleus and the outermost electrons increases.

Moreover, even though the positive charge in the nucleus (atomic number) also increases, the added inner electrons create a shielding effect. This shielding reduces the effective nuclear charge felt by the outermost electrons, allowing them to be located further from the nucleus. As a result, the overall size of the atom increases as you move from one element to the next within the same group. The increase in atomic radius is a fundamental trend in the periodic table, reflecting the arrangement and interaction of electrons in relation to the nucleus.