Four different radioactive isotopes are prepared such that their samples all initially emit radiation at the same rate. As time passes, the rate of emission decreases for each of the samples.
The half-lives of the four isotopes are shown in the table below:
| Isotope | Half-life |
|---|---|
| Xenon-135 | 9.1 hours9.1\text{ hours}9.1 hours |
| Sodium-24 | 15 hours15\text{ hours}15 hours |
| Gold-198 | 2.7 days2.7\text{ days}2.7 days |
| Cobalt-60 | 5.3 years5.3\text{ years}5.3 years |
Which sample of isotope has the greatest decrease in its rate of emission?
Xenon-135
Sodium-24
Gold-198
Cobalt-60
144 exam-style questions on CIE IGCSE Physics 5.2.4a Half-life. Each one has a worked solution and a mark scheme showing where the marks go.