# A neutral atom of carbon-14 has a mass number of 14 and an atomic number of 6. State the number of protons, neutrons, and electrons in this atom, and explain why carbon-14 is described as an isotope of carbon-12.

> AQA GCSE Physics (8463) — 4.4.1 Atoms and isotopes · Explain · 4 marks

## Mark scheme (4 marks)

1. The atom contains 6 protons
2. The atom contains 8 neutrons
3. The atom contains 6 electrons (because it is neutral / electrons equal protons in a neutral atom)
4. Carbon-14 and carbon-12 have the same number of protons / same atomic number but different numbers of neutrons / different mass numbers

## Key terms

- [mass number](https://www.gradenine.co.uk/glossary/mass-number)
- [atomic number](https://www.gradenine.co.uk/glossary/atomic-number)
- [neutrons](https://www.gradenine.co.uk/glossary/neutrons)
- [protons](https://www.gradenine.co.uk/glossary/protons)
- [electrons](https://www.gradenine.co.uk/glossary/electrons)

## Related

- [Revision notes for AQA GCSE Physics (8463)](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-neutral-atom-of-carbon-14-has-d91a15bf) · Published by Druglandscape Ltd.