A decommissioning engineer is assessing a legacy alloy specimen recovered from a nuclear waste storage silo. To determine the nature of its emissions, she positions a Geiger-Müller (GM) tube connected to a counter at a fixed distance and records the count-rate under various shielding configurations.
The table below shows the observed count-rates:
| Shielding configuration | Count-rate (counts per minute) |
|---|---|
| No shielding (air only) | 7800 |
| Single sheet of thin card | 5100 |
| 5 mm aluminium plate | 1200 |
| 5 cm lead block | 80 |
Analyze this data to explain how it demonstrates that the legacy alloy specimen emits all three types of ionising radiation: alpha (α\alphaα), beta (β\betaβ), and gamma (γ\gammaγ). Your response should include quantitative references to the changes in count-rate.
81 exam-style questions on Edexcel GCSE Physics 6.1 Atomic structure and isotopes. Each one has a worked solution and a mark scheme showing where the marks go.