# Rutherford's alpha particle scattering experiment led to the nuclear model of the atom. Describe the key conclusions Rutherford drew from the results of this experiment, and state the evidence from the experiment that supports each conclusion.

> Cambridge International IGCSE Physics (0625) — 5.1 The nuclear model of the atom · Describe · 4 marks

> In Rutherford's experiment, a beam of alpha particles was directed at a thin gold foil. Most alpha particles passed straight through, some were deflected at small angles, and a very small number were deflected straight back.

## Mark scheme (4 marks)

1. The atom is mostly empty space, supported by most alpha particles passing straight through the foil.
2. The nucleus is positively charged, supported by alpha particles being repelled/deflected.
3. The nucleus is very small, supported by only a very small number of alpha particles being deflected straight back.
4. The nucleus contains most of the mass of the atom, supported by alpha particles being deflected straight back.

## Key terms

- [nuclear model](https://www.gradenine.co.uk/glossary/nuclear-model)
- [alpha particle](https://www.gradenine.co.uk/glossary/alpha-particle)

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Source: [GradeNine](https://www.gradenine.co.uk/q/rutherford-s-alpha-particle-scattering-experiment-led-90998857) · Published by Druglandscape Ltd.