A radioactive isotope emits β\betaβ-particles.
The table below shows the activity of the isotope at different times:
| time / days | activity / counts per second |
|---|---|
| 0.0 | 800 |
| 10.0 | 200 |
| 20.0 |
What is the half-life of the isotope and what is the missing activity value at 20.0 days?
half-life =5.0 days= 5.0\text{ days}=5.0 days; activity =0 counts per second= 0\text{ counts per second}=0 counts per second
half-life =5.0 days= 5.0\text{ days}=5.0 days; activity =50 counts per second= 50\text{ counts per second}=50 counts per second
half-life =10.0 days= 10.0\text{ days}=10.0 days; activity =0 counts per second= 0\text{ counts per second}=0 counts per second
half-life =10.0 days= 10.0\text{ days}=10.0 days; activity =50 counts per second= 50\text{ counts per second}=50 counts per second
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.