Which of the following states an important result of Rutherford's gold-foil experiment?

A. Atoms have mass.

B. Electrons have a negative charge

C. Neutrons are uncharged particles

D. The atom is mostly empty space

Rutherford's gold-foil experiment showed that D. the atom is mostly empty space.

When he shot α particles at a thin gold foil, most of them went straight through the foil without being deflected.

However, a few of the α particles were deflected by rather large angles. He concluded that the atom is mostly empty space with almost all its mass concentrated in a small central nucleus.

The answer is d, the atom is mostly empty space