Answer:
The correct answer is option 4.
Explanation:
Bond length is the distance between the nucleus of atom to the nucleus of another atom bonded to it.
Bond order is defined as number of bonded electrons present in between the bond of atoms.
Bond length is inversely proportional to the bond order.
[tex]\text{Bond lenght}\propto \frac{1}{\text{Bond order}}[/tex]
Oxygen has double bond which means that it has bond order of 2 that is 4 electrons.
Nitrogen has triple bond which means that it has bond order of 3 that is 6 electrons.
Out of nitrogen and oxygen nitrogen has high bond order. As we know that higher the bond order shorter will be the bond length . So, nitrogen molecules has shorter bond length than oxygen molecule.