You might try an atomic or nuclear physics book. Simply stated, by bombarding the foil with alpha particles, Rutherford demonstrated that nucleii are very small, and that atoms are mostly space. The so called plum pudding model was disproved.
Bohr, who worked with Rutherford, saved the idea of a "planatary model" of the atom, with the astonishing idea of quantum stability, and derived the formulas of the hydrogen spectra to substantial accuracy. Rutherford discovered the nucleus, Thompson discovered the electron, and Bohr gave the first successful theory of the atom based on electrons and nucleii.
Regards
Reilly Atkinson