Electronegativity’s role in determining bond strengths needs to be rethought

Textbook knowledge about how to determine the strengths of chemical bonds seems to be oversimplified. Chemical bonds are usually stronger between atoms that have a larger difference in their electronegativity — which is influenced by the number of protons in the nucleus and the organisation of the electrons. But in some cases, researchers have found that differences in the sizes of the atom, rather than their electronegativity, determine the bond strength. The stability and length of chemical bonds are key factors in molecules’ structure and reactivity, so understanding them is important for developing everything from pharmaceuticals to materials.