One reason is that nitrogen has a triple bond between its atoms, whereas oxygen has a double bond. This means that the nitrogen molecule is much more stable than the oxygen molecule, and it takes more energy to break the nitrogen bond than the oxygen bond. This higher bond energy means that nitrogen is less likely to react with other elements.
Another reason why nitrogen is less reactive is that it has a higher ionization energy than oxygen. This means that it takes more energy to remove an electron from a nitrogen atom than from an oxygen atom. This higher ionization energy also makes nitrogen less likely to react with other elements.
Finally, nitrogen is a non-polar molecule, whereas oxygen is a polar molecule. This means that nitrogen does not have a partial positive charge or a partial negative charge, whereas oxygen does. This lack of polarity makes nitrogen less likely to react with other elements.
