Question 1

The alpha particle scattering experiment led to the nuclear model of the atom. Figure 5 shows the paths of alpha particles travelling close to a gold nucleus. Complete the sentences. Choose answers from the box.

attracts	decreases	does not change
increases	reflects	repels

1. Alpha particles and gold nuclei are both positively charged. The gold nucleus __________ the alpha particles. 2. As the alpha particle approaches the gold nucleus, the electric field strength experienced by the alpha particle __________. 3. As an alpha particle approaches the gold nucleus, the force experienced by the alpha particle __________.

Accepted Answer

1. Recall the rule for electrostatic forces: like charges repel, opposite charges attract. Alpha particles are positive, and the nucleus is positive. What force will exist between them?
2. Think about field strength. Is an electric field stronger or weaker closer to the charge that creates it?
3. Think about the force. According to Coulomb's Law (or just general principles), does the force between two charges get stronger or weaker as they get closer?

Question 2

What mistakes do candidates make on this AQA GCSE question?

Accepted Answer

✗ Choosing "attracts" - this would only happen if one charge was positive and the other negative.
✗ Choosing "decreases" for field strength or force. It's a common misconception to think the force gets weaker as things get closer, but the opposite is true for electrostatic and gravitational forces.

How to approach this question

Full Answer

Common mistakes

Practice the full AQA GCSE Physics Foundation Tier Paper 1

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