# Describe the structure of an atom, including the relative charges and masses of the particles found inside it.

> AQA A-Level Physics (7408) — 3.2.1 Particles · Describe · 5 marks

## Mark scheme (5 marks)

1. The atom has a nucleus at its centre (with electrons surrounding/orbiting it)
2. The nucleus contains protons and neutrons
3. Proton has a relative charge of +1 and neutron has a relative charge of 0
4. Electron has a relative charge of −1
5. Protons and neutrons each have a relative mass of 1 (approximately), whereas electrons have a negligible / very small mass (or relative mass of 1/1836 / approximately 0)

## Key terms

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

## Related

- [Revision notes for AQA A-Level Physics (7408)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" 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/describe-the-structure-of-an-atom-8b62dd38) · Published by Druglandscape Ltd.