Question

In Rutherford scattering experiment, what will be the scattering angle for an $\alpha$ particle for an impact parameter $b=0$ ?

• A. ${90}^{\circ }$
• B. $0^{\circ }$
• C. ${270}^{\circ }$
• D. ${180}^{\circ }$

Answer 1

The correct option is D ${180}^{\circ }$

Impact parameter is defined as the perpendicular distance between the direction of incident $\alpha -$ particle and the centre of the target nucleus.

For an impact parameter $b=0$, $\alpha -$particles are directed towards the centre of the target nucleus and hence, it retraces its path backward and are scattered at an angle of ${180}^{\circ }$.

$\therefore \alpha \left(\theta \right)={180}^{\circ }$.

Hence, option $\left(\text{D}\right)$ is correct.