
Answer: D. The new model fits the data better than the old model.
Explanation: Rutherford's gold foil experiment (firing positively charged particles at a thin gold foil) found that most of the particles went right through the atom except at a small center we now call the nucleus. Â This determined that the center of the atom had a positive charge, thus the electrons must be outside of the center. Â Rutherford's discovery of the nucleus and proposed atomic structure was later refined by physicist Niels Bohr in 1913. The Bohr model is still used today.