Final answer:
The size of the atomic orbital and the distance of an electron from the nucleus increase as the principal quantum number, n, increases, reflecting higher energy levels and weaker electrostatic attraction.
Step-by-step explanation:
As the principal quantum number (n) increases, the average distance between the nucleus and the electron within an atom also increases. This increase in n is associated with higher energy levels and less electrostatic attraction between the nucleus and the electron, resulting in the electron being held less tightly. As you move down a column in the periodic table, the atomic radii increase because the valence electron shell expands due to the larger principal quantum number, which indicates that the valence shell is physically farther from the nucleus. This is a reflection of the fact that atomic orbitals get larger as the value of n increases, and the electrons occupy shells with greater average distances from the nucleus.