The isoelectronic species `K^(+),Cl^(-),S^(2-)` and `Ca^(2+)` can be arranged in the following decreasing order of size:

Options

A. `Ca^(2+)gtK^(+)gtCl^(-)gtS^(2-)`
B. `Cl^(-)gtS^(2-)gtK^(+)gtCa^(2+)`
C. `S^(2-)gtCl^(-)gtCa^(2+)gtK^(+)`
D. `S^(2-)gtCl^(-)>K^(+)gtCa^(2+)`

Answer

D

Explanation

Size decreases with increase in nuclear charge in an iso -electronic series. The nuclear charge increases as:
`(S^(2-)" "Cl^(-)" "K^(+)" "Ca^(2+)),(+16" "+17" "+19" "+20)`