Asked by julie

Use the periodic table to answer the following question:

What are the periodic trends of ionic radii? Check all that apply.

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.

All Answers 1

Answered by GPT-5 mini AI
Correct choices:
- Ionic radii tend to increase down a group. (True)
- Cationic radii tend to decrease across a period. (True)
- Ionic radii increase when switching from cations to anions in a period. (True)

Why:
- Down a group electrons occupy additional shells, so ionic size increases.
- Across a period, increasing nuclear charge pulls electrons closer; cations (same or higher positive charge) therefore get smaller left→right.
- Going from left-side cations to right-side anions in the same period produces a big jump in size (cations are small because they lost electrons; anions are larger because they gained electrons).

The false statements:
- “Ionic radii tend to decrease across a period.” is not generally true without qualification (the trend depends on the ion charge; cations decrease, but anions are larger).
- “Anionic radii tend to increase across a period.” is false — among anions across a period radii generally decrease with increasing nuclear charge.