A reading is taken every 8 hours of the number of emissions per second from a radioactive source. The table shows the readings:
| Time / hours | Number of emissions per second |
|---|---|
| 0 | 1600 |
| 8 | 1130 |
| 16 | 800 |
| 24 | 565 |
| 32 | 400 |
| 40 | 283 |
| 48 | 200 |
What is the half-life of the source?
8 hours
16 hours
24 hours
32 hours
484 exam-style questions on CIE IGCSE Physics 5.2 Radioactivity, covering 5.2.1 Background radiation and measuring count rate, 5.2.2a Alpha, beta and gamma emission, 5.2.2b Deflection and ionising effects of nuclear radiation, 5.2.3a Radioactive decay, 5.2.3b Effects of decay on the nucleus and decay equations, 5.2.4a Half-life, 5.2.4b Choosing isotopes for applications, and 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.