Bond order is a measure of the strength of a chemical bond. It is calculated by dividing the number of bonding electrons by the total number of electrons in the bond. For example, the bond order of F2 is 1 because there is one bonding electron between the two fluorine atoms.
Bond order is an important concept in chemistry because it can be used to predict the properties of a molecule. For example, molecules with high bond orders are typically more stable and less reactive than molecules with low bond orders. Bond order can also be used to explain the different types of chemical bonds, such as sigma bonds and pi bonds.