What is the correct order of decreasing size of the following ions? A)P ³⁻ Cl ⁻ K ⁺ Ca ²⁺ B)Ca ²⁺ K ⁺ Cl ⁻ P ³⁻ C)K ⁺ Cl ⁻ Ca ²⁺ P ³⁻ D)K ⁺ Cl ⁻ P ³⁻ Ca ²⁺ E)None of these choices are correct.

Question

What is the correct order of decreasing size of the following ions? A)P ³⁻> Cl ⁻> K ⁺> Ca ²⁺ B)Ca ²⁺> K ⁺ > Cl ⁻ > P ³⁻ C)K ⁺ > Cl ⁻> Ca ²⁺ > P ³⁻ D)K ⁺> Cl ⁻ > P ³⁻> Ca ²⁺ E)None of these choices are correct.

Quizplus · Accepted Answer

The correct order of decreasing size for the given ions is based on the principle that, within a period, the size of ions decreases with increasing positive charge and increases with increasing negative charge due to changes in electron count and effective nuclear charge. Here, $P^{3-}$ is the largest due to its additional electrons and reduced effective nuclear charge, followed by $Cl^-$, which is smaller due to being closer to the noble gas configuration with fewer added electrons. $K^+$ is smaller than $Cl^-$ because it has lost an electron, leading to a greater effective nuclear charge on the remaining electrons. $Ca^{2+}$ is the smallest because it has lost two electrons, further increasing the effective nuclear charge on the remaining electrons, making it more compact.

What Is the Correct Order of Decreasing Size of the Following