What conclusion did Rutherford draw about the position and characteristics of the atom’s positively charged part based on the few alpha particles that bounced back or were deflected at large angles in the gold foil experiment?
Based on the few alpha particles that bounced back or were deflected at large angles, Rutherford concluded that the positive charge of an atom is not spread throughout but remains concentrated in an extremely small region called the nucleus.
Since very few alpha particles experienced large deflections, it indicated that the nucleus is extremely small in size. Rutherford calculated that the nucleus is about times smaller than the atom, with a diameter of approximately 10^-15 m compared to the atom's diameter of approximately 10^-10 m.
The sharp deflections also showed that the nucleus is dense and contains all the positive charge and most of the mass of the atom. If the positive charge were spread out evenly as Thomson's model suggested, alpha particles would not have bounced back or deflected so sharply.
Explanation
The question specifically asks about conclusions drawn from the few alpha particles that bounced back or were deflected at large angles. The context clearly states Rutherford concluded that the positive charge is concentrated in an extremely small region called the nucleus, not spread throughout. The large-angle deflections indicated the nucleus is dense and contains most of the mass. The fact that very few particles bounced back showed the nucleus is extremely small ( times smaller than the atom). This directly contradicted Thomson's plum pudding model which predicted only slight deflections.
Solution Steps
Step 1: Identify that few alpha particles bouncing back means the positive charge occupies a very small region (nucleus)
Step 2: Connect large-angle deflections to the nucleus being dense with most of the atom's mass and all positive charge
Step 3: Note the extremely small size of nucleus (10^-15 m) compared to atom (10^-10 m) explains why so few particles were deflected