In a Rutherford scattering experiment when a projectile of charge $Z_1$ and mass $M_1$ approaches a target…
In a Rutherford scattering experiment when a projectile of charge $Z_1$ and mass $M_1$ approaches a target nucleus of charge $Z_2$ and mass $M_2$, the distance of closest approach is $r_0$. The energy of the projectile is :
Directly proportional to mass $M_1$
Directly proportional to $\mathrm{M}_1 \times \mathrm{M}_2$