An archaeologist is using a Geiger-Müller (GM) counter to measure the radioactivity of an ancient glazed pottery shard.
She holds the detector in a fixed position close to the shard and records the readings shown in the table below.
| Time (minutes) | Detector reading (counts/minute) |
|---|---|
| 0 to 1 | 34 |
| 1 to 2 | 29 |
| 2 to 3 | 35 |
| 3 to 4 | 31 |
| 4 to 5 | 33 |
| 5 to 6 | 28 |
Explain the fluctuations in the detector readings.
The glaze on the pottery shard contains a radioisotope that emits both α\alphaα-particles and β\betaβ-particles. To handle the shard, the archaeologist wears thick safety gloves made of dense rubber.
Explain why wearing these gloves provides some protection from the radiation, but is not sufficient for complete safety.
42 exam-style questions on CIE IGCSE Physics 5.2.5 Effects of ionising radiation and safety precautions. Each one has a worked solution and a mark scheme showing where the marks go.