The correct order of decreasing ionic radii among the following isoelectronic species is

Options

A. `K^(+) lt Ca^(2+) gt C1^(-) gt S^(2-)`
B. `Ca^(2+) gt K^(+) gt S^(2-) gt C1^(-)`
C. `C1^(-) gt S^(2-) gt Ca^(2+) gt K^(+)`
D. `S^(2-) gt C1^(-) gt K^(+) gt Ca^(2+)`

Answer

D

Explanation

Among isoelectronic ions , ionic radii decreases as the magnitude of - ve charge decreases or the magnitude of + ve charge increases . Thus ionic radii decreases in the order ,i.e., `S^(2-) gt C1^(-) gt K^(+) gt Ca^(2+)` i.e., option (d) is correct.