The total number of isoelectronic species from the given set is \_\_\_\_ $\mathrm{O}^{2-}, \mathrm{F}^{-}, \mathrm{Al}, \mathrm{Mg}^{2+}, \mathrm{Na}^{+}, \mathrm{O}^{+}, \mathrm{Mg}, \mathrm{Al}^{3+}, \mathrm{F}$

JEE Main · 2023 · 15 Apr 2023 · Shift 1 · Atomic Structure

The total number of isoelectronic species from the given set is ____

O^{2 -}, F^{-}, Al, Mg^{2 +}, Na^{+}, O^{+}, Mg, Al^{3 +}, F

Answer: 5

Solution

Isoelectronic species have the same number of electrons. Counting electrons: O²⁻ (10), F⁻ (10), Al (13), Mg²⁺ (10), Na⁺ (10), O⁺ (7), Mg (12), Al³⁺ (10), F (9). The species with 10 electrons are: O²⁻, F⁻, Mg²⁺, Na⁺, and Al³⁺. Total = 5 isoelectronic species.

JEE Main · 2023 · 15 Apr 2023 · Shift 1 · Integer answer

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