Atomic Structure (Physics) Thomson's Model Thomson's tried to explain about the arrangement of +ve & -ve charges in an atom. An atom is a +vely charged sphere of diameter about 10 − 10 − 10 m is which +ve charge are uniformly distributed where as -ve charges are slightly embedded like plum in a pudding. This model is also called plum-pudding model. He explained unequal concentration of electric change. Atom is electrically neutral, the concentration of electric charge must be equal. This model could not explain about the atomic stability. This model could not explain about α -particle scattering experiment. Hence, this model is fails to exist Rutherford's Model Rutherford's carried out of α α particle scattering experiment and achieved the following observation. Observation Most of α α -particles cross thin gold foil without any deflection. Some of α α -particles are deflected with particular angle i.e. less than 90 0 0 i.e. acu...