Question

Identify the correct order of the size of the following:
(a) Ca²⁺ < K⁺ < Ar < Cl⁻ < S²⁻
(b) Ar < Ca²⁺ < K⁺ < Cl⁻ < S²⁻
(c) Ca²⁺ < Ar < K⁺ < Cl⁻ < S²⁻
(d) Ca²⁺ < K⁺ < Ar < S²⁻ < Cl⁻

Answer 1

Identify the correct order of the size of the following:- Ca²⁺ < K⁺ < Ar < Cl⁻ < S²⁻

- the atoms given in the question are isoelectronic

- for the isoelectronic species, the size of anion increases on the increase of negative charge

- the size of cation decreases with the increase of the positive charge

- also, for the isoelectronic species, the ionic radii of cations is less than that of the anions.

- therefore, the correct order is Ca²⁺ < K⁺ < Ar < Cl⁻ < S²⁻

- so the correct option is (a)