Question

Which of the following ion is isoelectronic with $O^{2-}$?

• A. $N^{3-}$
• B. $N^{+}$
• C. $F^{-}$
• D. $T{i}^{+3}$

Answer 1

Answer: (A), (C)

The correct options are
A $N^{3-}$
C $F^{-}$

Isoelectronic means species with same number of electrons.

$O^{2-}$ has 10 electrons ($8+2=10$).

$N^{3-}$ has 10 electrons ($7+3=10$).

So $O^{2-}$ is isoelectronic with $N^{3-}$.

Hence option A is correct.