# Explain why a static charge builds up when two insulating materials are rubbed together, and why the same effect does not occur when two conducting materials are rubbed together.

> Edexcel GCSE Physics (1PH0) — 11.1 Static electricity (Phys only) · Explain · 4 marks

## Mark scheme (4 marks)

1. Rubbing transfers electrons from one insulating object to the other
2. One insulator gains electrons giving it a negative static charge, and the other loses electrons giving it a positive static charge
3. In insulators, electrons are fixed and cannot flow through the material, so the charge cannot be cancelled out and remains as static charge
4. In conductors, electrons are free to move (delocalised), so any charge that builds up quickly flows away, keeping the conductors neutral

## Key terms

- [static charge](https://www.gradenine.co.uk/glossary/static-charge)

## Related

- [Revision notes for Edexcel GCSE Physics (1PH0)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-a-static-charge-builds-6953a7d1) · Published by Druglandscape Ltd.