For a dialogue between the philosophy of chemistry and the teaching of chemistry: the case of electronegativity

Electronegativity (EN) is an old but valuable concept that has multiple applications. The information it provides is very useful for predicting and explaining the physicochemical properties of a species. However, the fact that it cannot be measured directly was one of the reasons that led to a proliferation of very diverse models that coexist in scientific practice and, along with this, to a misunderstanding of what the very notion of EN implies. The purpose of this paper is to analyze two classical models of EN, Pauling and Mulliken, to show the incompatibility between them.