Thomson’s model could not explain these observations. In thomson’s model, electrons are spread throughout the surface of the atom. Therefore, all the alpha particles should be deflected in a similar way, but this did not happen. Thomson’s model had to be modified. To explain why most alpha particles passed straight through the gold, Rutherford suggested that the atom must be mostly empty space. He also suggested that there is small, dense object at a centre of the atom. This would explain why some of the alpha particles bounced straight back. Table 6.2 explains the observations made in Rutherford’s experiment.