Question
Explain why some a-particles will be deflected through large angles when a beam of a-particles is directed at a thin gold foil.
Answer
When a beam of alpha particles is directed at a thin gold foil, some alpha particles will be deflected through large angles because the gold atoms in the foil have a positively charged nucleus that repels the positively charged alpha particles. The deflection occurs due to the electrostatic repulsion between the positively charged nucleus and the positively charged alpha particle, causing them to scatter at large angles.