Volume 2 of the 5-volume Quantum Nanochemistry presents fundamental and advanced concepts, principles, and models as well as their first and novel combinations and applications in quantum (physical) and chemical theory of atomic structure. It exposes the atom’s perspective of quantum structures, spanning its diverse analytical predictions by historical and in-depth quantum analysis of the atomic periodicities of the atomic radii, ionization potential, electron affinity, electronegativity, and chemical hardness, along with the recently consecrated electrophilicity and chemical action.