Question

After Rutherford bombarded gold foil with alpha particles, he concluded that the volume of an atom is mostly empty space. Which observation led Rutherford to this conclusion?
1. Some of the alpha particles were deflected 180 degrees
2. The paths of deflected alpha particles were hyperbolic.
3. Many alpha particles were absorbed by gold nuclei.
4. Most of the alpha particles were not deflected.

Answer 1

Answer: 4. Most of the alpha particles were not deflected.

Explanation:

Rutherford gave an experiment known as gold foil experiment.

In his experiment, he took a gold foil and bombarded it with alpha particles (carrying positive charge). He thought that the particles will pass straight through the foil, but to his surprise, many of them passed through, some of them deflected their path and a few of them bounced back.

Due to the presence of positive charge on the alpha particles they must be deflected, but as there exists a large empty space as most of the alpha particles pass through without deflection.  

Answer 2

4)
Because if it doesn't deflect in the middle it means that there has to be some space for the alpha particles to go through it.