Who proposed the plum pudding model of the atom?

Who proposed the plum pudding model of the atom?

• A. J.J. Thomson
• B. Ernest Rutherford
• C. Niels Bohr
• D. James Chadwick

Answer: (A)

The idea behind the plum pudding model is that an atom is a sphere of positive charge with electrons embedded inside, like plums in a pudding. This view was proposed by J.J. Thomson after his discovery of the electron, suggesting the positive charge is spread out to balance the negative electrons and make the atom neutral. It was an early attempt to explain how atoms could be overall neutral and how their parts might be arranged. Later experiments, such as Rutherford’s gold foil test, showed that most of the atom’s mass and positive charge are actually concentrated in a tiny central nucleus, leading to a different nuclear model. Bohr then added the idea of quantized electron orbits, and Chadwick identified the neutron, refining the picture of the atomic nucleus. So the plum pudding model was proposed by J.J. Thomson.

The idea behind the plum pudding model is that an atom is a sphere of positive charge with electrons embedded inside, like plums in a pudding. This view was proposed by J.J. Thomson after his discovery of the electron, suggesting the positive charge is spread out to balance the negative electrons and make the atom neutral. It was an early attempt to explain how atoms could be overall neutral and how their parts might be arranged. Later experiments, such as Rutherford’s gold foil test, showed that most of the atom’s mass and positive charge are actually concentrated in a tiny central nucleus, leading to a different nuclear model. Bohr then added the idea of quantized electron orbits, and Chadwick identified the neutron, refining the picture of the atomic nucleus. So the plum pudding model was proposed by J.J. Thomson.