In which of the following cases, the value of impact parameter (for alpha particle scattering experiment by Geiger-Marsden) will be minimum ?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → head on collision of $α$-particle with nucleus
Head on collision means that the alpha particle is directed straight towards the nucleus, which results in the smallest possible impact parameter. In this case, the alpha particle will have the closest approach to the nucleus and experience the strongest repulsive force.