A paramagnetic molecule among the following is:

1.	O2–	2.	CN–
3.	NO+	4.	CO

Isostructural pair among the following is:

1. ${\mathrm{BCl}}_3$ $\mathrm{and}$ ${\mathrm{BrCl}}_3$

2. ${\mathrm{NH}}_3$ $\mathrm{and}$ ${\mathrm{NO}}_3^{-}$

3. ${\mathrm{NF}}_3$ $\mathrm{and}$ ${\mathrm{BF}}_3$

4. ${\mathrm{BF}}_4^{-}$ $\mathrm{and}$ ${\mathrm{NH}}_4^{+}$

The bond order of 1.5 is shown by:  

Which of the following has the minimum bond length?

1.  ${\mathrm{O}}_2^{-}$

2.  ${\mathrm{O}}_2^{2-}$

3.  ${\mathrm{O}}_2$

4.  ${\mathrm{O}}_2^{+}$

A molecule/ion among the following species that does not exist under normal conditions is:

In which of the following molecules/ions BF₃, ${\mathrm{NO}}_2^{-}$,  ${\mathrm{NH}}_2^{-,\hspace{0.17em}}$and H₂O, the central atom is sp² hybridized?

1. $N{O}_2^{-}$ $and$ $N{H}_2^{-}$

2. $N{H}_2^{-}$ $and$ $H_{2}O$

3. $N{O}_2^{-}$ $and$ $H_{2}O$

4. $B{F}_3$ $and$ $N{O}_2^{-}$

In which of the following molecules are all the bonds not equal?

Which of the following species has a linear shape?

1. $N{O}_2^{-}$

2. $S{O}_2$

3. $N{O}_2^{+}$

4. $O_3$

A diatomic molecule, among the following species, that only has $\mathrm{\pi }$ bonds according to the Molecular Orbital Theory (MOT) is:

Which of the following is a polar molecule?