Rutherford atomic model

Rutherford atomic model, description of the structure of atoms proposed (1911) by the British physicist Ernest Rutherford. The model described the atom as a tiny, dense, positively charged corecalled a nucleus, in which nearly all the mass is concentrated, around which the light, negative constituents, called electrons, circulate at some distance, much like planets revolving around the Sun. TheRutherford atomic model has been alternatively called the nuclear atom, or the planetary model of the atom.
The nucleus was postulated as small and dense to account for the scattering of alphaparticles from thin gold foil, as observed in a series of experiments performed under Rutherford’s direction in 1910–11 (see Figure). The diagram shows a simplified plan of his gold foil experiment. Aradioactive source capable of emitting alpha particles (i.e., positively charged particles more than 7,000 times as massive as electrons) was enclosed within a protective lead shield.
[The RutherfordModel of the Nuclear Atom]
Considering the results of Geiger and Marsden's experiment and the failure of Thomson's atomic model, E. Rutherford (UK, 1871 - 1937) proposed a model in which theelectric charge +Ze in an atom is not distributed over the whole area of the atom but concentrates in a small area (1911).
He thought as follows: The charge +Ze is localized to be acluster or a group and the alpha particle is scattered by Coulomb's repulsive force, (C. A. de Coulomb: France, 1736 - 1806). Namely, his idea is that the large-angle scattering of the alphaparticle is brought about by a single scattering due to Coulomb's repulsive force between the charge of the alpha particle, +2e, and that of the cluster, +Ze. The cluster is called atomicnucleus or simply nucleus. Rutherford's atomic model is often called Rutherford model or sometimes Rutherford model of the nuclear atom.
A schematic image of the Rutherford model is shown in...