# Describe the properties of beta radiation that make it suitable for use in thickness monitoring of aluminium sheets in a factory.

> OCR GCSE Physics A: Gateway Science (J249) — P4.3 Radioactive emissions · Describe · 4 marks

> A factory produces aluminium sheets of a fixed thickness. A beta source is used to monitor whether the sheet thickness remains constant during manufacture. The count rate detected on the other side of the sheet is used to check the thickness.

## Mark scheme (4 marks)

1. Beta particles are fast-moving electrons emitted from the nucleus
2. Beta radiation has a medium penetrating power / can pass through thin aluminium sheets
3. If the sheet becomes too thick, the count rate decreases / if the sheet becomes too thin, the count rate increases
4. Alpha would be stopped by the aluminium sheet / gamma would pass straight through and not be affected by small thickness changes, so beta is the most suitable

## Key terms

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

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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-the-properties-of-beta-radiation-99f0e7ff) · Published by Druglandscape Ltd.