# Magnesium has an atomic number of 12 and a mass number of 24. Describe the structure of a magnesium atom, including the number and location of each type of subatomic particle.

> Eduqas GCSE Chemistry — 2.1 Bonding, structure and properties · Describe · 4 marks

## Mark scheme (4 marks)

1. Magnesium has 12 protons (located) in the nucleus
2. Magnesium has 12 neutrons (located) in the nucleus
3. Magnesium has 12 electrons
4. Electrons are found in shells / energy levels surrounding / orbiting the nucleus

## Key terms

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

## Related

- [Revision notes for Eduqas GCSE Chemistry](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/magnesium-has-an-atomic-number-of-4d554656) · Published by Druglandscape Ltd.