Which from following species does not have number of electrons similar to other three species?

Question

Aicharya · Accepted Answer

$\begin{aligned} & \mathrm{Ne}=10=1 \mathrm{~s}^2 2 \mathrm{~s}^2 2 \mathrm{p}^6 \ & \mathrm{O}^{2-}=10=1 \mathrm{~s}^2 2 \mathrm{~s}^2 2 \mathrm{p}^6 \ & \mathrm{Na}^{+}=10=1 \mathrm{~s}^2 2 \mathrm{~s}^2 2 \mathrm{p}^6 \ & \mathrm{Na}=11=1 \mathrm{~s}^2 2 \mathrm{~s}^2 2 \mathrm{p}^6 3 \mathrm{~s}^1\end{aligned}$

Which from following species does not have number of electrons similar to other three species?

Solution