What did Rutherford and Marsden discover from the results of their scattering experiment?

Ernest Rutherford and Hans Geiger, along with Ernest Marsden, conducted the gold foil experiment, also known as the Geiger-Marsden experiment, to study the structure of the atom. Here are the steps of their discovery:

1. Experiment Setup: They directed a beam of alpha particles at a thin gold foil and detected the scattered particles on a fluorescent screen.

2. Observation: They observed that most of the alpha particles passed straight through the foil, some were deflected slightly, and a few were deflected at large angles.

3. Initial Hypothesis: According to the plum pudding model of the atom proposed by J.J. Thomson, all alpha particles should have passed straight through the foil with little or no deflection.

4. Contradiction: The observation that a few alpha particles were deflected at large angles contradicted the plum pudding model.

5. Rutherford's Interpretation: Rutherford interpreted this to mean that the positive charge and most of the mass of the atom were concentrated in a small central nucleus, with the electrons orbiting around it. This was a major departure from the plum pudding model, which proposed that the positive charge was spread evenly throughout the atom.

6. Conclusion: The results of the gold foil experiment led Rutherford to propose a new model of the atom, known as the nuclear model, which is the basis for our modern understanding of atomic structure.