# A student uses a gold-leaf electroscope to investigate static electricity. The metal cap of the electroscope is touched with a negatively charged rod. The gold leaf rises and stays raised after the rod is removed. Explain why the gold leaf rises and remains raised.

> AQA A-Level Physics (7408) — 3.7.3 Electric Fields · Explain · 5 marks

> A gold-leaf electroscope consists of a metal cap connected by a metal rod to a thin gold leaf. When the leaf carries the same type of charge as the rod, it rises away from the rod.

## Mark scheme (5 marks)

1. Electrons transfer from the charged rod to the metal cap (and through the electroscope)
2. The electroscope (cap, rod and leaf) becomes negatively charged / gains excess electrons
3. The rod and the gold leaf both carry the same type of charge (both negative)
4. Like charges repel, so the gold leaf is pushed away from the rod
5. The leaf remains raised because the charge cannot escape / the electroscope is an electrical insulator from its surroundings / there is no conducting path to earth

## Related

- [Revision notes for AQA A-Level Physics (7408)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-uses-a-gold-leaf-electroscope-2a86e0bb) · Published by Druglandscape Ltd.