Question

What is bond order? How can we determine it? Please explain the basics. Thank you so much.

Answer 1

The bond order determines the number of chemical bonds between the two atoms in the molecule. The bond order is calculated by subtracting the number of electrons present in the bonding orbital by the electrons present in the antibonding orbital divided by two.

Complete step by step answer:
In molecular orbital theory, the bond order plays an important role in finding the bond strength of the chemical bond. The bond order measures the number of electrons involved in bond formation between the atom of the molecule.
Linus Pauling gave the bond order concept which gives the difference between the number of bonding electrons and number of anti bonding electrons.
On atomic level, the bond order is defined as the number of bonded electron pairs present between the two atoms. For the compounds like dinitrogen ${N_2}$ $N \equiv N$, It can be seen that three chemical bonds are present between the two nitrogen atoms. The bond order of dinitrogen is 3.
In molecular orbital theory, the bond order is defined as the half of the difference between the number of bonding electrons and antibonding electrons.
The formula of the bond order is shown below.
$Bond\;order = \dfrac{1}{2}[Number\;of\;bonding\;electrons - Number\;of\;antibonding\;electrons]$
The number of bond orders helps to know the strength of the bond. Greater is the number of bond orders, stronger is the bond. Lesser is the number of bond orders, weaker is the bond.

Note:
The bonding orbitals and antibonding orbitals is illustrated in the molecular orbital diagram. The molecular orbitals are formed by the overlap of atomic orbitals. The two atomic orbital overlaps in two ways which are bonding orbital and antibonding orbital.