Why N2 is more stable than O2. Explain on the basis of Molecular Orbital Theory

Molecular orbitals of nitrogen and oxygen is as below:
 
Nitrogen molecule has 14 electrons. So the electron distributions in molecular orbital are as below
 
N₂ = σ1s² σ*1s²   σ2s² σ*2s²  σ2p_x²   π(2p_y² 2p_z²)    
 
Bond order = (No. of electrons in bonding orbitals - No. of electrons in bonding orbitals)/2
                    =(10-4)/2 = 3
 
Oxygen molecule has 16 electrons. So the electron distributions in molecular orbital are as below
 
O₂ = σ1s² σ*1s²   σ2s² σ*2s²  σ2p_x²   π(2p_y² 2p_z²)  π*(2p_y¹ 2p_z¹)
 
 Bond order= (10-6)/2 = 2
 
As bond order of nitrogen is more than that of oxygen, nitrogen is more stable than oxygen.