Final answer:
Rutherford's experiment with alpha particle scattering by gold foil established that the positive charge in an atom is concentrated in a small space called the nucleus.
Step-by-step explanation:
Rutherford's experiment with alpha particle scattering by gold foil established that the positive charge in an atom is concentrated in a small space called the nucleus. Most of the alpha particles passed through the gold foil, indicating that the atom is mostly empty space. However, a small fraction of the particles were deflected, suggesting that they encountered another positive charge, which Rutherford concluded was the nucleus.