# Aluminium oxide is an ionic compound. Describe how aluminium and oxygen atoms form ions and explain what holds the ions together in the ionic compound.

> Cambridge International IGCSE Chemistry (0620) — 2.4 Ions and ionic bonds · Describe and Explain · 4 marks

## Mark scheme (4 marks)

1. Aluminium atom loses 3 electrons to form Al³⁺ ion
2. Oxygen atom gains 2 electrons to form O²⁻ ion
3. Oppositely charged ions are formed (one positive, one negative)
4. The ionic bond is the electrostatic attraction between the oppositely charged ions

## Key terms

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

## Related

- [Revision notes for Cambridge International IGCSE Chemistry (0620)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe and Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/aluminium-oxide-is-an-ionic-compound-b010d0cb) · Published by Druglandscape Ltd.