Question

Describe Thomson's concept of the atom?

Answer 1

Thomson atomic model was proposed by J.J Thomson in the year 1904 just after the discovery of electrons. According to the postulates of Thomson’s atomic model, an atom resembles a sphere of positive charge with electrons present inside the sphere. The positive and negative charge is equal and therefore an atom is electrically neutral. Thomson’s atomic model was compared to a spherical plum pudding as well as a watermelon. It was compared to a plum pudding because the electrons in the model look like the dry fruits embedded in a sphere of positive charge just like a spherical plum pudding. The model has also been compared to a watermelon because the red edible part of a watermelon was compared to the sphere having a positive charge and the black seeds filling the watermelon looked similar to the electrons inside the sphere.

Answer 2

In Thomson's model, the atom is composed of electrons surrounded by a soup of positive charge to balance the electrons' negative charges, like negatively charged "plums" surrounded by positively charged "pudding". The 1904 Thomson modelwas disproved by Hans Geiger's and Ernest Marsden's 1909 gold foil experiment.