Re-discussion on the Development of Electronegativity Scales

Electronegativity has been one of the most important concepts in chemistry. It plays a critical role in fundamental chemistry courses. This paper proposed a view of three periods on the development of electronegativity. The process of deepening and gradually developing in understanding of electronegativity scale is briefly described. On the basis of a brief description of different electronegativity scales, the difference between absolute electronegativity scale, Pauling type electronegativity scale, Allen electronegativity scale and its modified Rahm electronegativity scale were discussed emphatically. The re-discussion is undoubtedly helpful for the in-depth understanding about the concept of electronegativity and the reform of teaching contents in fundamental studies.