Question

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

• A. The entire positive charge and almost all the mass is concentrated over a small volume at the centre of the atom
• 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), (B), (C)

The correct options are
A The entire positive charge and almost all the mass is concentrated over a small volume at the centre of the atom
B Alpha particles are positively charged
C Most part of the atom is empty space

When alpha particles are sent through a thin metal foil, most of them go straight through the foil because most part of the atom is empty space. In other words, there is no obstruction in the path of alpha particles.
Note: The atom is extremely hollow. It consists of large empty space. The volume of nucleus is much smaller than atomic volume. An alpha particle is 7300 times heavier than an electron.