Place the following ions in order of decreasing radius. Te²⁻ F⁻ O²⁻ A) F⁻ O²⁻ Te²⁻ B) F⁻ Te²⁻ O²⁻ C) Te²⁻ O²⁻ F⁻ D) Te²⁻ F⁻ O²⁻ E) O²⁻ F⁻ Te²⁻

Question

Place the following ions in order of decreasing radius. Te²⁻ F⁻ O²⁻ A) F⁻ > O²⁻ > Te²⁻ B) F⁻ > Te²⁻ > O²⁻ C) Te²⁻ > O²⁻ > F⁻ D) Te²⁻ > F⁻ > O²⁻ E) O²⁻ > F⁻ > Te²⁻

Quizplus · Accepted Answer

The trend for ionic radii is to increase down a group and decrease across a period. The first three ions all contain the same number of electrons, but vary in the number of protons, which determines the effective nuclear charge experienced by the electrons. As a result, the ion with the greatest number of protons, F⁻, will have the smallest radius. Of the remaining two ions, Te²⁻ has a greater radius because the negative charge on the ion outweighs the effect of the additional protons compared to O²⁻. Therefore, the correct order is Te²⁻ > O²⁻ > F⁻.

Place the Following Ions in Order of Decreasing Radius