In the Rutherford alpha-scattering experiment, alpha particles were directed at a thin gold foil. Which option correctly pairs an observation from this experiment with the corresponding conclusion about atomic structure?
Observation: Most alpha particles passed straight through. Conclusion: The nucleus is positively charged.
Observation: Most alpha particles passed straight through. Conclusion: Most of the atom is empty space.
Observation: A very small fraction of alpha particles deflected at large angles. Conclusion: Electrons orbit in distinct shells.
Observation: A very small fraction of alpha particles deflected at large angles. Conclusion: Positive charge is spread evenly through the atom.
284 exam-style questions on CIE IGCSE Physics 5.1 The nuclear model of the atom, covering 5.1.1a Structure of the atom and ions, 5.1.1b Alpha-particle scattering, 5.1.2a Composition of the nucleus and isotopes, 5.1.2b Proton number, nucleon number and nuclide notation, and 5.1.2c Nuclear fission and nuclear fusion. Each one has a worked solution and a mark scheme showing where the marks go.