Question

When alpha particles are sent through a thin metal foil, most of them go straight through the foil because:

• A. alpha particles are positively charged.
• B. most part of the atom is empty.
• C. alpha particles move with the high velocity.
• D. alpha particles are much heavier than electrons.

Answer 1

Answer: (B)

• Because most of the $\alpha$-particles passed through the metal foil without getting deflected means most of the space inside the atom is empty.
• Very few particles were deflected from their path, indicating that the positive charge of the atom occupies very little space.
• A very small fraction of $\alpha$-particles were deflected by very large angles, indicating that all the positive charge and mass of the gold atom were concentrated in a very small volume within the atom.

Hence, option $C$ is correct.