Final answer:
Cations with larger charges have smaller radii than cations with smaller charges. As we move down the periodic table, cations of successive elements with the same charge generally have larger radii.
Step-by-step explanation:
Cations with larger charges are smaller than cations with smaller charges (e.g., V²+ has an ionic radius of 79 pm, while that of V³+ is 64 pm). Proceeding down the groups of the periodic table, we find that cations of successive elements with the same charge generally have larger radii, corresponding to an increase in the principal quantum number, n.