In Rutherford's alpha-particle scattering experiment, only a few alpha particles rebound back because
A. The size of gold nucleus is very small as compared to the size of gold atom.
B. Alpha particle and gold nucleus have equal charge.
C. The impact parameter is minimum for a few alpha particles.
D. A few alpha particles have very high kinetic energy.
E. Only a few alpha particles undergo head-on collision with the nuclei.
Choose the correct answer from the options given below :
Answer: (D) A, C, E Only
The nucleus is tiny compared with the atom (A), so only the few alpha particles aimed almost straight at it, i.e. with nearly zero impact parameter (C), make a near head-on collision (E) and bounce back.
B is false (the gold nucleus has charge $+79e$, the alpha $+2e$), and D is false (the beam is roughly monoenergetic).
Solution by Sreeraj P, M.Sc Physics