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 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

Option 4 is the correct answer. Rutherford concluded that the atom's volume was mostly empty space because the stream of alpha particles he directed at the gold foil arived at his detection aparatus mostly intact, indicating that relatively few of the alpha particles had been deflected. This follows because if the atom had not been empty space then the alpha particles would have encountered resistance and gone off course.