Question

Which particle was used in Rutherford's scattering experiment?

• A. Beta particles
• B. Alpha particle
• C. Electron
• D. Neutron

Answer 1

Answer:

B. Alpha particle

• Ernest Rutherford conducted the famous Alpha particle scattering experiment (also known as the Geiger-Marsden experiment) in 1911 to study the structure of the atom.

• The experiment involved bombarding a thin gold foil with a beam of high-energy alpha particles (helium nuclei, ⁴He²⁺) emitted from a radioactive source.

• Key observations:

  • Most alpha particles passed straight through the gold foil without deflection, indicating that the atom consists largely of empty space.

  • A small fraction of particles were deflected by small angles, suggesting the presence of a positive charge within the atom.

  • A very small number of particles (about 1 in 8,000) rebounded back, which led Rutherford to propose that the entire positive charge and most of the mass of the atom are concentrated in a very small volume called the nucleus.

• This experiment marked the discovery of the atomic nucleus and the eventual development of the Rutherford model of the atom (or planetary model), which visualized electrons orbiting a dense, positive nucleus.