Sealed sources J and K contain equal numbers of undecayed nuclei. J has a half-life of 8 days and K has a half-life of 8 years. Which statement is correct?
K has the greater activity because its nuclei last for far longer
J has the greater activity because its nuclei decay at a faster rate
J and K have equal activity because they contain equal numbers of nuclei
K has the greater activity because it stores more energy in total
40 exam-style questions on AQA GCSE Physics 4.2 Atoms and nuclear radiation, covering 4.2.1 Radioactive decay and nuclear radiation, 4.2.2 Nuclear equations, 4.2.3 Half-lives and the random nature of radioactive decay, and 4.2.4 Radioactive contamination. Each one has a worked solution and a mark scheme showing where the marks go.