The correct order of energies of molecular orbitals of N_2 molecule, is:

$\displaystyle \sigma 1 \mathrm{~s}<\sigma^* 1 \mathrm{~s}<\sigma 2 \mathrm{~s}<\sigma^* 2 \mathrm{~s}<\left(\pi 2 \mathrm{p}_{\mathrm{x}}=\pi 2 \mathrm{p}_{\mathrm{y}}\right)<$ $$\sigma 2 \mathrm{p}_{\mathrm{z}}<\left(\pi^* 2 \mathrm{p}_{\mathrm{x}}=\pi^* 2 \mathrm{p}_{\mathrm{y}}\right)<\sigma^* 2 \mathrm{p}_{\mathrm{z}} $$

$\displaystyle \sigma 1 \mathrm{~s}<\sigma^* 1 \mathrm{~s}<\sigma 2 \mathrm{~s}<\sigma^* 2 \mathrm{~s}<\sigma 2 \mathrm{p}_{\mathrm{z}}<$ $$\left(\pi 2 \mathrm{p}_{\mathrm{x}}=\pi 2 \mathrm{p}_{\mathrm{y}}\right)<\left(\pi^* 2 \mathrm{p}_{\mathrm{x}}=\pi^* 2 \mathrm{p}_{\mathrm{y}}\right)<\sigma^* 2 \mathrm{p}_{\mathrm{z}} $$

$\displaystyle \sigma 1 \mathrm{~s}<\sigma^* 1 \mathrm{~s}<\sigma 2 \mathrm{~s}<\sigma^* 2 \mathrm{~s}<\sigma 2 \mathrm{p}_{\mathrm{z}}<$ $$\sigma^* 2 \mathrm{p}_{\mathrm{z}}<\left(\pi 2 \mathrm{p}_{\mathrm{x}}=\pi 2 \mathrm{p}_{\mathrm{y}}\right)<\left(\pi^* 2 \mathrm{p}_{\mathrm{x}}=\pi^* 2 \mathrm{p}_{\mathrm{y}}\right) $$

$\displaystyle \sigma 1 \mathrm{~s}<\sigma^* 1 \mathrm{~s}<\sigma 2 \mathrm{~s}<\sigma^* 2 \mathrm{~s}<\left(\pi 2 \mathrm{p}_{\mathrm{x}}=\pi 2 \mathrm{p}_{\mathrm{y}}\right)<$ $$\left(\pi^* 2 \mathrm{p}_{\mathrm{x}}=\pi^* 2 \mathrm{p}_{\mathrm{y}}\right)<\sigma 2 \mathrm{p}_{\mathrm{z}}<\sigma^* 2 \mathrm{p}_{\mathrm{z}} $$