Explain the structure of the $O_2$ molecule.

Among $KO_2$,$KAlO_2$,$CaO_2$ and $NO_2^+$,unpaired electron is present in

The energy of $\sigma 2p_z$ molecular orbital is greater than $\pi 2p_x$ and $\pi 2p_y$ molecular orbitals in nitrogen molecule. Write the complete sequence of energy levels in the increasing order of energy in the molecule. Compare the relative stability and the magnetic behaviour of the following species : $N_2, N_2^+, N_2^-, N_2^{2+}$

Explain the difference between positive (bonding) and negative (antibonding) overlapping of orbitals.

What is the bond order of the $O_2$ molecule?

Match each of the diatomic molecules in Column $I$ with its property / properties in Column $II$.

Column $I$	Column $II$
$(A)$ $B_2$	$(p)$ Paramagnetic
$(B)$ $N_2$	$(q)$ Undergoes oxidation
$(C)$ $O_2^{-}$	$(r)$ Undergoes reduction
$(D)$ $O_2$	$(s)$ Bond order $\geq 2$
	$(t)$ Mixing of '$s$' and '$p$' orbitals