Some alpha particles fired through a gold foil bounce backward by
A)making direct hits with gold atoms.
B)electrostatic repulsion when close to gold nuclei.
C)electrostatic repulsion with the electron clouds of gold atoms.
D)all of these
E)none of these

Question

Quizplus · Accepted Answer

The best choice is B) electrostatic repulsion when close to gold nuclei. This is because alpha particles are positively charged and gold nuclei are also positively charged. When the alpha particles come close to the nucleus, they experience repulsion due to their like charges. Because the nucleus is extremely small and dense, there is a high likelihood that some of the alpha particles will be bounced backward. The other choices are partially correct but do not provide a complete explanation for why some alpha particles bounce backward.

Some Alpha Particles Fired Through a Gold Foil Bounce Backward