In chemistry, bond strength is the degree to which each atom is joined to another in a chemical bond contributes to the valency of this other atom. Bond strength is intimately linked to bond order and can be quantified by:
Another criterion of bond strength is the qualitative relation between bond energies and the overlap of atomic orbitals of the bonds (Pauling and Mulliken). The more these overlap, the more the bonding electrons are to be found between the nuclei and hence stronger will be the bond. Overlap is necessary for the formation of molecular orbitals. This overlap can be calculated and is called the overlap integral.