Averaged Scale in Electronegativity Joined to Physicochemical Perturbations. Consequences of Periodicity

Energy Electronegativity and Chemical Bonding

Historical development of the concept of electronegativity (EN) and its significance and prospects for physical and structural chemistry are discussed. The current cutting-edge results are reviewed: new methods of determining the ENs of atoms in solid metals and of bond polarities and effective atomic charges in molecules and crystals. The ENs of nanosized elements are calculated for the first time, enabling us to understand their unusual reactivity, particularly the fixation of N₂ by nanodiamond. Bond polarities in fluorides are also determined for the first time, taking into account the peculiarities of the fluorine atom's electronic structure and its electron affinity.

Cardinal Electronegativity Values Correlate with Physicochemical Properties

The use of the difference in electronegativity (EN) function is shown to be fundamentally untenable for differentiating ionic from covalent bonding in binary compounds. Also, the commonly used parameters of differences and averages of EN values do not provide a direct correlation with metallic, ionic, or covalent chemical bonding types. On the other hand, the cardinal coordinates of lower and higher EN values readily demonstrate such a correlation. Graphs and similar tables of these two parameters show how chemical bonding combines and separates a mixture of these three bonding types. The orthogonal axes of these two cardinal functions indicate that there are two separate contributors to bonding: a band-gap (conductive) and a polarity (insulative) component that together produce the variety of chemical bonding types. These characteristics arise from absolute and differential electronic potentials. This two-dimensional perspective provides the means for interpreting the nature of EN.