the nucleus is the atom, the electron shells fiction: Checkerboard-like Atoms

With the first nuclear-shell atomic model in history in 1911, Ernest Rutherford postulated a large atomic shell with electrically negative electrons and a small electrically positive atomic nucleus. He considered the atomic nucleus to be a single positive charge around which electrons orbit, or linger, at a great distance. He did not yet know that the atomic nucleus is composed of protons and neutrons. Thus the often quoted comparison of the atom with a planetary system is comprehensible. (...