Question

Consider the isoelectronic species, Na⁺, Mg²⁺,
F⁻ and O²⁻. The correct order of increasing length
of their radii is ________.
(a) F⁻ < O²⁻ < Mg²⁺ < Na+ (b) Mg2+ < Na⁺ < F⁻ < O²⁻
(c) O²⁻ < F⁻ < Na⁺ < Mg²⁺ (d) O²⁻ < F⁻ < Mg²⁺ < Na⁺

Answer 1

Answer:

Option a us right answer

Answer 2

(b) Mg2+ < Na⁺ < F⁻ < O²⁻

Explanation:

Isoelectronic species means the atoms or group of atoms that have the same number of electrons.

Amongst isoelectronic ions, the ionic radii decreases with the increase in nuclear charge. So Mg2+ (12) < Na+ (11) < F (10) < 02- (8).

Option B is the answer.