The magnetic property of $NO_2$ is

Use molecular orbital theory to explain why the $Be_{2}$ molecule does not exist.

According to molecular orbital theory,the species among the following that does not exist is

In which of the following transformations,the bond order has increased and the magnetic behaviour has changed?

The molecular orbital configuration of a diatomic molecule is
$\sigma 1s^2 \sigma^* 1s^2 \sigma 2s^2 \sigma^* 2s^2 \sigma 2p_x^2 \pi 2p_y^2 \pi 2p_z^2$
Its bond order is

Which of the following is paramagnetic?