Question

which of the following series of isoelectronic ions (mg²⁺, n³⁻, f⁻, si⁴⁺) has the ionic radii in order of largest to smallest?

Explanation:

Isoelectronic ions have the same number of electrons. The ionic radius decreases with an increase in the nuclear charge (number of protons).

• For \(N^{3 -}\), \(F^{-}\), \(Mg^{2+}\), \(Si^{4+}\), the number of electrons is 10.
• The nuclear charge: \(N(7)\), \(F(9)\), \(Mg(12)\), \(Si(14)\).
• As the nuclear charge increases, the attraction for electrons increases, and the ionic radius decreases.

Answer:

D. \(N^{3 -}>F^{-}>Mg^{2+}>Si^{4+}\)