Which of the following ions, has smallest size?

Question

Which of the following ions, has smallest size? (A)  Ca2+  (B)  Cl-  (C)  S2-  (D)  K+

Tardigrade Admin · Accepted Answer

Ca2+, Cl-, S2- and K+ are isolectronic species. In isoelectronic ions, size decrease with increasing nuclear charge. Hence, Ca2+ ion is the smallest among these.

Q. Which of the following ions, has smallest size?

$C a^{2 +}$

$C l^{-}$

$S^{2 -}$

$K^{+}$

$C a^{2 +}, C l^{-}, S^{2 -}$ and $K^{+}$ are isolectronic species. In isoelectronic ions, size decrease with increasing nuclear charge. Hence, $C a^{2 +}$ ion is the smallest among these.