$\mathrm{Ne}_{2}(\mathrm{Z}=10) 1 s^{2} 2 s^{2} 2 p^{6} .$ In $\mathrm{Ne}_{2}$ valence orbital 8 electrons and affected in bond structure are 16 electrons.

Electron configuration in $\mathrm{MO}$ for $\mathrm{Ne}_{2}$ :

$\mathrm{KK}(\sigma 2 s)^{2}\left(\sigma^{*} 2 s\right)\left(\pi 2 p_{z}\right)^{2}\left(\pi 2 p_{x}\right)^{2}=\left(\pi 2 p_{y}\right)^{2}\left(\pi^{*} 2 p_{x}\right)^{2}=\left(\pi^{*} 2 p_{y}\right)^{2}\left(\sigma^{*} 2 p_{z}\right)^{2}$

Bond order $=\frac{1}{2}\left(\mathrm{~N}_{\mathrm{b}}-\mathrm{N}_{\mathrm{a}}\right)=\frac{1}{2}(10-10)=0$

$\mathrm{BO}$ is zero, So ti is unstable means does not exist. Energy diagram for $\mathrm{Ne}_{2}$ :