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 :
- A
A, B Only
- B
B, E Only
- C
C, D Only
- D
A, C, E Only
Rebounding (large-angle backscatter) requires a near head-on collision with a concentrated positive nucleus. So:
(A) Correct — the nucleus is far smaller than the atom, so the chance of a near head-on encounter is tiny.
(B) Incorrect — alpha (+2e) and gold nucleus (+79e) do not carry equal charge.
(C) Correct — only alphas with very small impact parameter come close enough to be repelled backward.
(D) Incorrect — in the original experiment all alphas come from the same source with the same kinetic energy.
(E) Correct — only the small fraction that effectively hit head-on are turned back.
A, C, E only.
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