Question

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

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

Answer 1

Answer: (A), (C)

The correct options are
A $\alpha$- particles are much heavier than electrons
C most part of the atom is empty space

Rutherford concluded from the -particle scattering experiment that :

(i) Most of the space inside the atom is empty because most of the $\alpha$-particles passed through the gold foil without getting deflected.

(ii) Very few particles were deflected from their path, indicating that the positive charge of the atom occupies very little space.
(iii) 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, options A & C are correct.