Atomic structure plum-pudding model

This experiment eliminated the plum pudding model as a possible structure of the atom. But what did an atom look like Rutherford figured that the only way to make alpha particles bounce backward... 

It was apparent to Thomson that if atoms in the metal electrode contained negative particles (electrons), they must also contain positive charges because atoms are electrically neutral. Thomson proposed a model for the atom in which positive and negative particles were embedded in some sort of matrix. The model became known as the plum pudding model because it resembled plums embedded in a pudding. Somehow, an equal number of positive and negative particles were held in this material. Of course we now know that this is an incorrect view of the atom, but the model did account for several features of atomic structure. 

It was perhaps Thomson who first suggested a specific structure for the atom in terms of subatomic particles. His plum pudding model (ca. 1900), which placed electrons in a sea of positive charge, like raisins in a pudding., accorded with the then-known facts in evidently permitting electrons to be removed under the influence of an electric potential. The modem picture of the atom as a positive nucleus with extranuclear electrons was proposed by Rutherford13 in 1911. It arose from... 

Thomson s "Plum Pudding" Model of Atomic Structure... 

The plum pudding model, a batter of positive charge with minute negative currants embedded in it, appeared to be consistent with experiments which showed that a beam of electrons could pass undeflected through a thin metallic foil. In other words, one might conclude, as Philipp Lenard (1862-1947) did in 1903, that the atom was mostly empty space. These data as well as the larger question about the inner structure of the atom prompted a most provocative line of experimentation by Ernest Rutherford (1871-1937). Manchester University was the site of these historical experiments, which Rutherford initiated soon after he arrived in 1907 to assume his responsibilities as Langworthy Professor of Physics. 

Figure 2.2 The structure of the atom (a) J. J. Thomson s Plum Pudding model (b) N. Bohr s model...

The purpose of this first computer laboratory is to review some of the fundamental concepts from classical physics, to understand what constitutes a solution to a problem in classical physics, and to introduce students to numerical solutions for the Newtonian equations of motion. QuickBASIC programs have been written which use PC graphics to display the trajeaory of an electron in the Thomson plum pudding model of the atom, the Bohr atom, and a classical model for the hydrogen-molecule ion. This early review of classical physics helps students appreciate more fully how fundamentally different quantum theory is. The material in this exercise is frequently used as a leaure demonstration to support a classroom lecture on the precursors to the quantum theory of atomic and molecular structure. 

What is meant by a nuclear atom Describe the points of Rutherford s model for the nuclear atom and how he tested this model. Based on his experiments, how did Rutherford envision the structure of the atom How did Rutherford s model of the atom s structure differ from Kelvin s "plum pudding" model ... 

The presence of electrons in all matter posed some major questions about the structure of atoms. Matter is electrically neutral, so atoms must be also. But if atoms contain negatively charged electrons, what positive charges balance than And if an electron has such a tiny mass, what accounts for an atom s much larger mass To address these issues, Thomson proposed his plum-pudding model— a spherical atom composed of diffuse, positively charged matter with electrons embedded like raisins in a plum pudding. ... 

In 1904 ].] Thomson (Nobel Prize in Physics in 1906) surveyed the experimental evidence suggesting that atoms consist of charged particles. He described the atom as a uniform (always the same) sphere of positive electricity and mass, in which negative electrons are embedded. This model was known as the plum pudding model of atomic structure (Figure 2.5). 

---