Alpha Particles
Physics: AQA GCSE Higher, topic 3.1.5
The Scattering of Alpha Particles
Ernest Rutherford discovered the nucleus by firing a beam of alpha particles at thin metal foils (only a few atoms wide).
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Rutherford's experiment
- Most alpha particles passed straight through the foil.
- This suggested that most of the atom is made up of empty space.
- However, some particles bounced back towards the source.
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Rutherford's conclusions
- The large deflections suggested that some positively charged mass in the atom was repelling the particles.
- This led to the model of the atom with negatively charged electrons orbiting a positively charged nucleus.
Test yourself on Alpha Particles
Who discovered the nucleus of the atom?
Which of the following are true of Rutherford's experiment that discovered the nucleus?
Why would the alpha particles be deflected by a smaller angle if the thin metal foil was made of a lighter element?