History of the Atom Interactive

Explore how atomic models changed over time, then perform Rutherford’s alpha particle scattering experiment yourself.

Timeline of atomic theory

Click a stage to open a detailed pop-up showing the model, key idea, and how the theory developed.

GCSE focus: You need to know the development up to Bohr’s electron shell model. The quantum model is included as extension so students can see science continued to develop.

Rutherford’s alpha particle scattering experiment

Fire alpha particles at thin gold foil and observe how they behave.

Then click the three key observations to see the explanation and diagram.

What is happening?

The radioactive source emits positively charged alpha particles towards a very thin sheet of gold foil.

Most particles pass straight through, but some are deflected because they pass close to the nucleus.

Observed results and conclusions

1. Most alpha particles went straight through

Conclusion: atoms are mostly empty space.

Click for picture
2. Some alpha particles were deflected

Conclusion: the nucleus is positively charged.

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3. A tiny number bounced back

Conclusion: the nucleus is very small and very dense, about 1 × 10⁻¹⁵ m.

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