What is the Bond Order of N2 (Nitrogen)?

The bond order of N₂ is 3.

This means that the two nitrogen atoms are held together by a triple bond (one sigma bond and two pi bonds). Written as: N ≡ N.

To prove this scientifically, chemists use Molecular Orbital Theory (MOT).

1. A single Nitrogen atom (Atomic number 7) has 7 electrons. So, the N₂ molecule has 14 electrons in total.
2. We distribute these 14 electrons into molecular orbitals according to increasing energy levels: σ1s², σ1s², σ2s², σ2s², π2px² = π2py², σ2pz²

The Formula: Bond Order = ½ × [ (Number of electrons in Bonding orbitals, Nb) − (Number of electrons in Anti-bonding orbitals, Na) ]

Looking at the configuration:

• Bonding electrons (Nb) = 2 (1s) + 2 (2s) + 6 (2p) = 10
• Anti-bonding electrons (Na) = 2 (*1s) + 2 (*2s) = 4

Calculation: Bond Order = ½ × (10 − 4) Bond Order = ½ × 6 Bond Order = 3

The bond order is directly proportional to bond stability.

• Because the bond order of N₂ is 3 (a triple bond), it requires a massive amount of energy (941 kJ/mol) to break the two nitrogen atoms apart.
• This high bond enthalpy is the reason why nitrogen gas (which makes up 78% of our atmosphere) is chemically inert (unreactive) under normal conditions.