Radioactive waste contains two isotopes, J and K. The table shows information about them.
Table
| Isotope | Activity now (Bq) | Half-life (years) |
|---|---|---|
| J | 32 00032\,00032000 | 10 |
| K | 4 0004\,0004000 | 50 |
Which statement about the activities of J and K after 100 years100\ \text{years}100 years is correct?
J has the higher activity, because it starts with a much higher activity
J and K have equal activities, because both have decayed for 100 years100\ \text{years}100 years
K has the higher activity, because it has been through fewer half-lives
K has the lower activity, because it starts with a much lower activity
48 exam-style questions on OCR GCSE Physics 6.2 Uses and hazards, covering 6.2.1 Contamination and irradiation, 6.2.2 Half-life and radiation hazards, 6.2.3 Medical uses of nuclear radiation, 6.2.4 Nuclear fission and chain reactions, and 6.2.5 Nuclear fusion. Each one has a worked solution and a mark scheme showing where the marks go.