An experiment is carried out to investigate the absorption of radiation emitted from a radioactive source. The source and detector are placed approximately 2 cm apart in air, and a scaler is used to measure the count rate. Different absorbing sheets are placed in the gap between the source and the detector, yielding the following results:
| Absorbing material | Count rate (counts/s) |
|---|---|
| Air | 840 |
| Single sheet of paper | 840 |
| 1.0 mm of aluminium | 512 |
| 15 mm of aluminium | 247 |
| 20 mm of lead | 85 |
Explain how the data shows that the source does not emit α\alphaα-particles.
Describe the evidence indicating that β\betaβ-particles are emitted by the source.
Describe the evidence indicating that γ\gammaγ-rays are emitted by the source.
134 exam-style questions on CIE IGCSE Physics 5.2.2a Alpha, beta and gamma emission. Each one has a worked solution and a mark scheme showing where the marks go.