Rutherford's Alpha Particle Scattering Experiment

Steps:

• Identify the experiment: This describes Rutherford's gold foil experiment, which revealed the atom's nuclear structure.
• Recall the method: Beams of particles were fired at thin gold foil to probe atomic structure.
• Analyze results: Most particles passed through undeflected, but some scattered at large angles, indicating a tiny, dense nucleus.
• Match to choices: The scattered particles were alpha particles, confirming the nuclear model.

Why A is correct:

• Alpha particles, being massive helium nuclei, scattered off the gold nucleus, as per Rutherford's scattering formula, proving the nucleus's small size and mass concentration.

Why the others are wrong:

• B: Beta particles are electrons, too light for significant scattering to reveal nuclear density.
• C: Gamma radiation is electromagnetic waves, not particles that scatter to show matter distribution.
• D: Gold nuclei were the targets, not the scattered projectiles.

Final answer: A