# Explain why electrons in an atom can be found at different distances from the nucleus, and describe what happens to an electron when it absorbs energy.

> AQA A-Level Chemistry (7405) — 3.1.1 Atomic structure · Explain · 5 marks

## Mark scheme (5 marks)

1. Electrons occupy shells (energy levels) around the nucleus
2. Different shells are at different distances from the nucleus / shells are at fixed distances from the nucleus
3. When an electron absorbs energy it moves to a higher energy level / shell further from the nucleus
4. The electron then returns to a lower energy level / its original shell, releasing energy
5. The energy released is emitted as electromagnetic radiation / light

## Related

- [Revision notes for AQA A-Level Chemistry (7405)](https://www.gradenine.co.uk/learn)
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