Fire alpha particles past a nucleus and vary the aim. A near head-on approach is repelled through a large angle; a distant one barely bends, just as Rutherford found.
MissionPredict how an alpha particle aimed nearly head-on at the nucleus is deflected.Streak 0Best 0
An alpha particle aimed nearly straight at the nucleus is:
impact parameter70 (relative)
deflection angle–
A close approach to the small, positive nucleus gives a strong Coulomb repulsion and a large deflection.