This question most likely has answer choices. The possible answer choices are as followed:
- Ionic radii tend to increase down a group.
- Ionic radii tend to decrease across a period.
- Anionic radii tend to increase across a period.
- Cationic radii tend to decrease across a period.
- Ionic radii increase when switching from cations to anions in a period.
The answers are Ionic radii tend to increase down a group, Cationic radii tend to decrease across a period, and Ionic radii increase when switching from cations to anions in a period (1st, 4th, and 5th options).