Question

If impact parameter is very small, then scattering angle is around

• A. zero
• B. $90^{\circ }$
• C. $180^{\circ }$
• D. $360^{\circ }$

Answer 1

Answer: (C)

$\alpha$-particle close to the nucleus (small impact parameter) suffers large scattering. In case of head-on collision, the impact parameter is minimum and the $\alpha$-particle rebounds back $(\theta \cong \pi )$. For a large impact parameter, the $\alpha$-particle goes nearly undeviated and has a small deflection $(\theta \cong 0)$.