Which statement best describes the design of Rutherford's gold foil experiment?

• A. A beam of electrons was passed through a gold foil to measure its electrical conductivity.
• B. A gold foil was dissolved in acid to study its chemical reactivity.
• C. A beam of alpha particles was directed at a thin sheet of gold foil, and the scattering of the particles was observed on a fluorescent screen.
• D. Gold atoms were heated in a vacuum to observe their emission spectra.

Answer: (C)

Verified step by step guidance

1. Understand the historical context: Rutherford's gold foil experiment was designed to investigate the structure of the atom, specifically to test the plum pudding model and explore the distribution of positive charge within the atom.
2. Identify the key components of the experiment: a source of alpha particles (which are helium nuclei), a very thin sheet of gold foil, and a detection screen (fluorescent screen) to observe the scattering pattern of the alpha particles after they pass through or are deflected by the foil.
3. Recognize the purpose of using alpha particles: because they are positively charged and relatively massive, their deflection patterns can reveal information about the presence of a dense, positively charged nucleus within the atom.
4. Note the observations made: most alpha particles passed straight through the foil, but some were deflected at large angles, indicating that the positive charge and most of the atom's mass are concentrated in a small central nucleus.
5. Conclude that the correct description of the experiment is: a beam of alpha particles was directed at a thin sheet of gold foil, and the scattering of the particles was observed on a fluorescent screen, which led to the nuclear model of the atom.