# A science museum exhibit displays two radioactive samples side by side. A label states that Sample A has an activity of 5 200 Bq and Sample B has an activity of 52 000 Bq. Explain what the unit becquerel means and describe what the difference in activity values tells us about the two samples.

> Pearson Edexcel International GCSE Physics (4PH1) — 7.1 Units · Explain · 4 marks

> A science museum exhibit displays two radioactive samples side by side. Sample A has an activity of 5 200 Bq and Sample B has an activity of 52 000 Bq.

## Mark scheme (4 marks)

1. The becquerel (Bq) is the unit of (radioactive) activity
2. One becquerel equals one (nuclear) decay per second
3. Activity is the rate at which unstable nuclei decay / the number of decays per unit time
4. Sample B has a higher activity than Sample A, so its unstable nuclei are decaying at a faster rate (ten times faster / 52 000 decays per second compared with 5 200 decays per second)

## Key terms

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

## Related

- [Revision notes for Pearson Edexcel International GCSE Physics (4PH1)](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-science-museum-exhibit-displays-two-f31c5958) · Published by Druglandscape Ltd.