Stability of molecules : If $\mathrm{N}_{\mathrm{b}}>\mathrm{N}_{\mathrm{a}}$, means a stable molecule while $\mathrm{N}_{\mathrm{b}}<\mathrm{N}_{\mathrm{a}}$, means an unstable molecule so, stability $\propto$ bond order.

Bond order : $\frac{1}{2}$ ( $\mathrm{N}_{\mathrm{b}}-\mathrm{N}_{\mathrm{a}}$ )

Nature of bond : Integral bond order values of 1,2 and 3 correspond to single, double or triple bonds respectively.

Bond length : The bond length decrease of bond order increase.

Magnetic nature : If all the molecular orbitals in a molecule are doubly occupied, the substance is diamagnetic (repelled by magnetic field). If one order more molecular orbitals are singly occupied it is paramagnetic (attracted) by magnetic field), e.g. $\mathrm{O}_{2}$ molecule.

Where, $\mathrm{N}_{\mathrm{a}}=$ Number of electrons in antibonding orbitals.

$\mathrm{N}_{\mathrm{b}}=$ Number of electrons in bonding orbitals.

$\mathrm{BO}=$ Bond order