What Was J.J. Thomson’s Atomic Model?

J.J. Thomson’s atomic atomic model was called the Plum Pudding Atomic Model, and it was based on the idea that electrons are negatively charged particles scattered through out the positively charged atom. While Thomson was right about the existence of electrons, he was wrong on where they are located within the atom.

Thomson compared the way that the electrons are scattered throughout the atom to the raisins of a plum pudding. This theory suggested that the negative and positive charges in the atom existed in the same sphere of existence, but it wasn’t until 1911 that the location of the nucleus that housed these charges was discovered. The man who discovered the nucleus, Ernest Rutherford, was a student of Thomson at one time and was actually testing Thomson’s theory when he made his own discovery: rather than being scattered throughout the atom, electrons orbit a positively charged nucleus. Once Rutherford had discovered that particles in foil were able to deflect the H2+ particles in 1911, the plum pudding model was set aside for Rutherford’s model. Thomson also abandoned his own model to support Rutherford’s model.

Throughout Thomson’s career, he held a number of distinguished positions due to his discoveries. He was given a knighthood in 1908 by the British Royal family in addition to a Nobel Prize in 1906. Even though Thomson’s plum pudding theory was disproved, many of the elements of his discoveries such as electrons were key to finding and building the model that is used currently.