Question

The size of isoelectronic species — F^–, Ne and Na⁺ is affected by

(a) Nuclear charge (Z )

(b) Valence principal quantum number (n)

(c) Electron-electron interaction in the outer orbitals

(d) None of the factors because their size is the same.

Answer 1

The size of an isoelectronic species increases with a decrease in the nuclear charge (Z). For example, the order of the increasing nuclear charge of F^–, Ne, and Na⁺ is as follows:

F^– < Ne < Na⁺

Z 9 10 11

Therefore, the order of the increasing size of F^–, Ne and Na⁺ is as follows:

Na⁺ < Ne < F^–