Redefinition of Electronegativity as the Average Valence Electron Energy

Electronegativity (EN) has been redefined as the average valence electron energy (AVEE) that takes into account all of the s and p electrons in the valence shell for main group elements. This definition confers unambiguous physical meaning on the term electronegativity. EN and AVEE can be used interchangeably, directly relating the parameter to the periodicity of the elements. This paper shows that the EN criterion can be used as an exclusive approach to describing the properties and reactivities of the elements. Various chemical phenomena, such as metallicity, reactivity, type of bonding, and oxidation states, are correlated distinctly to electronegativity. Especially significant is the explanation of the difference in properties of the second row and lower main group elements based exclusively on their electronegativities. This is demonstrated to be a simple and powerful approach that possibly avoids more complicated bonding theories. Electronegativity (in terms of average valence electron energy) qualifies as the third dimension of the periodic table. The purpose of this paper is to effectively address this concept in fundamental chemical education in relation to the periodicity and properties of the elements.