Structure of Atom: The Space inside an Atom is not empty!

   In a perfectly isolated atom, there are two types of forces acting on its electrons. They are attraction from the nucleus and repulsion between electrons (in hydrogen atom attraction from the nucleus only). But these forces cannot cause any kind of motion of electrons in an atom; in fact the widely accepted model of atom is not consistent with the theoretical and experimental observations. Since electrons are not moving there must be a force which prevents the electrons from falling into the positive charged nucleus.
   Volume of atoms (E.g., hydrogen atom still possesses volume even after stripping off its electron) and elastic nature of atoms (E.g, gas atoms move randomly in high speed and bounce when they collide with other atoms or its container) indicate that the nucleus of an atom is surrounded by a form of elastic matter. I name this matter as "space matter". So there are three factors that determine the electron configuration in a multi-electron atom. They are: a) attraction from the nucleus, b) repulsion between electrons and c) buoyant force exerted by space matter. [The electron configuration in a hydrogen atom is determined by two factors - Attraction from the nucleus and buoyant force by space matter]. Buoyant force is the only force that prevents the innermost electrons of an atom from falling into the nucleus. The electrons other than one nearest to the nucleus, repulsion with the electrons in the inner region as well as the buoyant force exerted by space matter keep the electrons in an atom in its respective positions.
   Since an atom of an element creates its own characteristic pattern of spectrum lines when excited, and in cold state the same atom creates absorption lines in the same frequencies that the atom creates its emission lines, we can conclude that the electrons in an atom are situated in resonant columns.
   When a low-energy electron collides with a multi-electron atom, the atom emits long wavelength radiations. But when a high-energy electron collides with the same atom, the atom can emit both shorter and longer wavelength radiations. As a low-energy electron can only excite an atom's outer electrons, a high-energy electron is capable of penetrating outer region of the atom and to excite inner electrons. So we can understand that, the space matter density in the inner region of an atom is greater and it decreases with the increasing distance from the nucleus and also, this difference in densities creates different resonant columns in an atom.