Unlike the situation in the solar system, where planet-planet
gravitational forces are very small as compared to the gravitational
force of the sun on each planet (because the mass of the sun is so
much greater than the mass of any of the planets), the electron-electron
electric force interaction is comparable in magnitude to the electron-
nucleus electrical force, because the charges and distances are of the
same order of magnitude This is the reason why the Bohr’s model
with its planet-like electron is not applicable to many electron atoms 5 Bohr laid the foundation of the quantum theory by postulating specific
orbits in which electrons do not radiate