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Physics Paper 1 · P4 · Lesson 4.10

Choosing radiation and reducing risk

Use penetration and ionisation to explain a choice.

Key ideas1 of 4

Match the radiation to the job

For checking paper thickness, beta can be useful: some passes through the paper to a detector. Thicker paper absorbs more, so the detected count rate falls. Alpha would be stopped too easily.

A beta source is on the left, paper passes through the middle, and a detector is on the right. Some radiation is absorbed by the paper.

The source and detector positions stay fixed.

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Topic resources and sources

Daily 5 · Core exam practice · Higher Tier questions · A4 revision sheet

Lessons 4.1–4.10 cover the core. Lesson 4.11 is Higher Tier only. Daily 5 practises core facts. Answer positions are shuffled on each new attempt; lessons begin with very simple questions.

AQA Combined Science Trilogy specification · 6.4.2.1 and 6.4.2.4. Original notes, questions and diagrams. Experimental numbers are illustrative.

Photos: Geiger counter by Boffy b, enhanced by Marco Plassio; caesium source by Wusel007, enhanced by Partynia, both CC BY-SA 3.0. Rutherford at McGill, 1905, unknown photographer / Wellcome Images, public domain. Photos displayed without cropping or other alterations.