The Electron Periodic Table: A Chemical Element Classification System Based on Electron Interface Characteristics

This paper proposes and systematically constructs a chemical element classification system based on electron interface characteristics—the Electron Periodic Table—within the constraint network framework of Energy Ontology. The traditional periodic table defines element identity by proton number, treats isotopes as variants of the same element, and cannot derive the numerical regularities of groups and periods from first principles. Starting from the axiom system of constraint network dynamics, this paper demonstrates that the chemical identity of an element is determined by the electron interface characteristics of its nuclear node—the Φ directionality, number, and sealing intensity of the interfaces. The Electron Periodic Table uses Φ directionality type as its horizontal axis, interface sealing intensity as its vertical axis, and total nuclear aggregate number (isotopes) as its depth axis. The number of groups is determined by the number of independent extremal directions in the Φ multipole expansion; the number of periods is determined by the hierarchical progression of electron interface sealing intensity. The Electron Periodic Table naturally accommodates isotopes—different isotopes within the same interface family are arranged along the depth axis according to their total nuclear aggregate number, with radioactivity being the process of returning to the stable attractor. This paper provides the complete positions, electron interface parameters, and chemical property predictions for all 118 elements in the Electron Periodic Table, systematically benchmarked against NIST bond angle data. The Electron Periodic Table is not a replacement for the traditional periodic table, but the emergent root from which the traditional periodic table arises. This work provides chemistry with the first complete framework derived from first principles for the classification of chemical elements.