Question

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.
done

Explanation:

• Down a group, additional electron shells are added, so ionic radii increase.
• Across a period, cations lose electrons and their nuclear charge pulls remaining electrons closer, so cationic radii decrease.
• When moving from cations to anions in a period, anions gain electrons, increasing electron-electron repulsion and adding a higher electron cloud volume, so ionic radii jump up.
• Anionic radii actually decrease across a period as nuclear charge increases while valence electron count stays similar for anions in the same period. The general "ionic radii decrease across a period" is incorrect because of the sharp increase between cations and anions.

Answer:

• Ionic radii tend to increase down a group.
• Cationic radii tend to decrease across a period.
• Ionic radii increase when switching from cations to anions in a period.