Why was the plum pudding model wrong in describing the structure of the atom?

The plum pudding model was wrong because it incorrectly suggested that the atom was a uniform, positively charged sphere with negatively charged electrons scattered throughout, like plums in a pudding. This model was disproven by the results of the Rutherford gold foil experiment, which showed that the atom has a small, dense, positively charged nucleus at its center, with electrons orbiting around it.