Hello, Is there any reason to believe an atom, say Hydrogen, is spherical via experiments, or is this merely a model for us to visualize with? Furthermore, can one prove that an atom is not a cube? Finally, is there any model in physics that can account for how a photon is emitted from a deexcited electron? Or do we still simply say that the photon is equal to the energy level drop and leave it at that? Thanks.