# Explain why atoms are electrically neutral, and describe what happens to the overall charge of an atom when it gains or loses electrons.

> WJEC A-Level Physics (Wales) — 1.7 Particles and nuclear structure · Explain · 5 marks

> Atoms contain charged particles but are normally found to have no overall electric charge. However, atoms can gain or lose electrons to form ions.

## Mark scheme (5 marks)

1. The nucleus contains protons, which have a positive charge
2. Electrons have a negative charge (and orbit/surround the nucleus)
3. In a neutral atom the number of protons equals the number of electrons, so the charges cancel / balance
4. When an atom gains electrons it becomes a negatively charged ion
5. When an atom loses electrons it becomes a positively charged ion

## Key terms

- [electrically neutral](https://www.gradenine.co.uk/glossary/electrically-neutral)
- [electron](https://www.gradenine.co.uk/glossary/electron)

## Related

- [Revision notes for WJEC A-Level Physics (Wales)](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/explain-why-atoms-are-electrically-neutral-3983e087) · Published by Druglandscape Ltd.