Thomson's model, known as the plum pudding model, proposed that the atom was a sphere of positive charge with negatively charged electrons embedded within it like plums in a pudding.
Geiger and Marsden's experiment, which involved firing alpha particles at a thin gold foil, showed that a significant number of the particles were deflected at large angles, some even bouncing back towards the source. This result contradicted Thomson's model, which predicted that the alpha particles would pass through the foil with minimal deflection.
The experiment led to the development of the nuclear model of the atom by Ernest Rutherford, which proposed that the atom has a small, dense, positively charged nucleus at its center, surrounded by negatively charged electrons.
