Based on the analysis of the well-known features of the atoms, the following conclusions can be deduced. The identical and invariant properties of the chemical elements can only be ensured if the charge distribution of the nucleus is invariant and identical for each of the elements, dynamic equilibrium between the opposite charges in the atoms cannot be stable in the time scale of the universe, classical electromagnetism is valid at atomic scale, since neither theory nor experiments sets limits on it. Taking these conclusions into consideration the following modifications of the contemporary atom models are proposed. Nucleus: The identical reproduction of the nucleus requires lattice arrangement for the nucleons. Protons and neutrons have the same size. These nucleons should occupy the space in the most efficient way, forming a closest packing arrangement. The smallest building blocks of this arrangement are tetrahedrons. Assuming alternate arrangement of the protons and the neutrons, and expanding a tetrahedron seed by adding additional layers to it, the number of protons in the layers reproduces the periodicity of the chemical elements. Electronegativity represents the average attraction of the unshielded proton/s on the valence electron/s. This physical description is even consistent with the irregularities of electronegativity. Electronic shell: In the time scale of the universe, dynamic equilibrium of the opposite charges in the atoms would be chaotic. This contradicts with the known stability of the atoms. Static equilibrium between the opposite charges can only be achieved if at least one of the charges is a distributed one. The physical behavior of the free and the bounded electrons are different. Thus, these electrons are not identical. These differences can be explained if the point charge free (unbounded) electron at capturing transfers and forms a surface charge electron shell around the nucleus, and vice versa. This phase transformation is energetically feasible. The electronic shell structure of the atoms is the consequence of the nuclear lattice. New electron shell is formed when the attraction of the added proton of an element is weaker on the captured electron than the average attraction on an electron in the existing shell.