The species A, K and Ca2+ contain the same number of electrons. In which order do their radii increase?

Question

The species ${Ar}, {K}^{+}$and ${Ca}^{2+}$ contain the same number of electrons. In which order do their radii increase?

(a) ${Ca}^{2+}<{K}^{+}<{Ar}$

(b) ${K}^{+}<{Ar}<{Ca}^{2+}$

(c) ${Ar}<{K}^{+}<{Ca}^{2+}$

(d) ${Ca}^{2+}<{Ar}<{K}^{+}$

Answer 1

Correct Option : (A)

Explanation —

In case of isoelectronic species, radius decreases with increase in nuclear charge.