Final answer:
Rutherford changed Thomson's plum pudding model into the nuclear model based on his gold foil experiment.
Step-by-step explanation:
Rutherford changed Thomson's plum pudding model into the nuclear model based on the evidence from his gold foil experiment. In this experiment, Rutherford bombarded alpha particles (a-particles) on a thin gold foil. According to Thomson's model, the alpha particles should pass through the gold foil un-deflected. However, Rutherford observed that some a-particles were deflected at large angles and even reflected directly back at the source. This observation led Rutherford to conclude that there is a small, dense region at the center of an atom called the nucleus, which contains most of the atom's mass and positive charge.