An organisation prepares sealed emergency surgical kits for use in temporary hospitals. Each kit contains several layers of instruments and is sealed before treatment. The kits pass through an irradiation chamber containing a gamma source.
Separate test kits from the same batch are opened for quality checks.
| Measurement | Before treatment | After treatment |
|---|---|---|
| Mean number of living microorganisms cultured per test instrument | 480 | 0 |
After treatment, the gamma source is moved behind concrete shielding. A detector is then used to measure the count rate.
| Detector position | Mean count rate in counts per minute |
|---|---|
| Away from any kit | 23 |
| Next to an unopened treated kit | 23 |
Explain why beta radiation would be less suitable than gamma radiation for this treatment.
Use the information and the results to explain why the treated kits can be stored until needed and handled safely.
97 exam-style questions on Edexcel GCSE Physics 6.5 Uses and dangers of radioactivity, covering 6.5.1 Uses of radioactivity, 6.5.2 Dangers of ionising radiation and precautions, 6.5.3 Half-life and radiation dangers, 6.5.4 Safety precautions for radiation exposure, and 6.5.5 Contamination and irradiation. Each one has a worked solution and a mark scheme showing where the marks go.