How did Rutherford figure out the structure of the atom without being able to see it? Simulate the famous experiment in which he disproved the Plum Pudding model of the atom by observing alpha particles bouncing off atoms and determining that they must have a small core. • Describe the qualitative difference between scattering off the positively charged nucleus and electrically neutral plum pudding atom. • For the charged nucleus, describe qualitatively how the angle of deflection depends on the energy of the incoming particle, the impact parameter, and the charge of the target.