# Sodium has the atomic number 11 and a relative atomic mass of approximately 23. State the number of protons, neutrons and electrons in a neutral sodium atom, and use these values to explain why sodium is electrically neutral.

> Pearson Edexcel International GCSE Chemistry (4CH1) — 1.3 Atomic structure · State and Explain · 4 marks

## Mark scheme (4 marks)

1. Sodium has 11 protons
2. Sodium has 12 neutrons
3. Sodium has 11 electrons (equal to the number of protons)
4. The atom is electrically neutral because the number of (negatively charged) electrons equals the number of (positively charged) protons, so the charges cancel / balance out

## Key terms

- [atomic number](https://www.gradenine.co.uk/glossary/atomic-number)
- [electron](https://www.gradenine.co.uk/glossary/electron)
- [neutron](https://www.gradenine.co.uk/glossary/neutron)
- [proton](https://www.gradenine.co.uk/glossary/proton)

## Related

- [Revision notes for Pearson Edexcel International GCSE Chemistry (4CH1)](https://www.gradenine.co.uk/learn)
- [How to answer "State and 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/sodium-has-the-atomic-number-11-e0a3fe84) · Published by Druglandscape Ltd.