In a scattering experiment, α\alphaα-particles are fired at a thin sheet of gold foil in a vacuum. Under these conditions, it is observed that a very small proportion of the α\alphaα-particles are deflected through large angles (greater than 90∘90^\circ90∘).
Which of the following is the correct conclusion that can be drawn from this specific observation?
The atom consists mostly of empty space.
The positive charge and almost all the mass of the atom are concentrated in an extremely small, dense nucleus.
Electrons carry a negative charge and orbit the nucleus at a large distance.
Neutrons are present in the nucleus to hold the protons together.
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.