Thomson’s Plum Pudding

The last big problem facing early twentieth century physics was Ernest Rutherford s atomic structure. Physicists knew that Rutherford s atom could not exist, but no one could come up with anything better. The man who would resolve this conundrum showed up at Manchester, England, in 1912 to work for Rutherford. Rutherford himself had worked for J.J. Thomson and had disproved Thomson s plum pudding structure of the atom. Now, the new man in Manchester, Niels Bohr, was about to do the same thing to Rutherford. By the end of his career, Bohr would have contributed as much as anyone to understanding Feynman s little particles. Science is a meritocracy. Poor kids can excel and get ahead in the world of science just as easily as the well-heeled. For example. 

Thomson s plum-pudding model of the atom. Thomson proposed that the atom might be made of thousands of tiny, negatively charged particles swarming within a cloud of positive charge, much like plums and raisins in an old-fashioned Christmas plum pudding. 

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

J.J. Thomson s plum pudding atomic model proposed that negatively charged electrons were distributed throughout a uniform positive charge. 

Thinking Critically Compare and contrast Thomson s plum pudding atomic model with Rutherford s nuclear atomic model. 

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

Figure 4.9 J. J. Thomson s plum pudding model of the atom states that the atom is a uniform, positively charged sphere containing electrons. 

Rutherford described Thomson s plum pudding model as being tike old lumber fit only for a museum of scientific curiosities. Source unknown to present author. 

In Thomson s plum pudding model, the pudding is made of... 

Why is Rutherford s nuclear model of the atom more con-CQ sistent with the results of his a-particle scattering experiment than Thomson s "plum-pudding" model ... 

In 1911 Ernest Rutherford (Fig. 2.11), who performed many of the pioneering experiments to explore radioactivity, carried out an experiment to test Thomson s plum pudding model. The experiment involved directing a particles at a thin sheet of metal foil. 

A clear example of empirical science is the falsifying of Thomson s plum pudding model by Rutherford s gold foil experiment. One issue is that some so-called scientific theories are non-falsifiable, for example string theory. Science can be demarcated from pseudoscience less by what science is, and more by what scientists do. Science is a set of methods aimed at testing hypotheses and developing theories. If the theory is adopted by the scientific community, then the chances are it is science. 

Thomson s plum-pudding model had protons and electrons scattered throughout the atom. 

---