Chloride ion and potassium ion are isoelectronic Then

Options

A. potassium ion is relatively bigger
B. depends on the other cation and anion
C. their sezes are same
D. chloride ion is bigger than potassium ion.

Answer

D

Explanation

`Cl^(-) and K^(+)` are isoelectric species having same number of electrons (=18). Greater the nuclear charge of an ion, more will be force of attraction for same number of electrons. `K^(+)` have greater nuclear charge than `Cl^(-)` so attractive pull exerted by the nucleus is more and the size is smaller in `K^(+)` ion.