Question

When $\alpha$-particle 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. $\alpha$-particle move with high velocity

Answer 1

Answer: (C)

most part of the atom is empty space

As most part of an atom is empty so collision rate is low and most of the particles go straight through the foil.
Also, alpha particles are heavier than electrons so they go straight and have small impact of collision.