Answer: Atoms are mostly empty with a tiny dense nucleus.
- A Atoms are mostly empty with a tiny dense nucleus
- B Electrons are embedded in uniform positive charge
- C Nucleus contains only neutrons
- D Atoms have no empty space
Correct answer: A. Atoms are mostly empty with a tiny dense nucleus
Explanation: Most alpha particles passed through; a few deflected greatly. This proved the atom is mostly empty space with a tiny, dense, positive nucleus.
The Geiger–Marsden alpha-scattering result: a few alpha particles bounce back at large angles, which rules out Thomson’s diffuse model and demands a tiny, massive, positively charged nucleus. Image: Kurzon, CC BY 3.0, via Wikimedia Commons.
Concept context
Thomson's plum-pudding model, Rutherford's nuclear model from alpha-scattering, Bohr's postulates and hydrogen spectrum, spectral series (Lyman to Pfund), Rydberg formula, and limitations of each model.