Two sealed sources, R and S, are stored in a laboratory. Each source contains 2.0 × 1020 undecayed nuclei. The half-life of source R is 5 days. The half-life of source S is 5000 years.
Explain which of the two sources has the higher activity.
A technician must work close to one of the sources for one hour. Explain which source gives the technician the smaller radiation dose during that hour.
Both sources must eventually be disposed of. Explain which source has to be stored safely for the longer time.
A student writes, "A source with a long half-life is always more dangerous than a source with a short half-life." Explain why this statement is not correct.
40 exam-style questions on AQA GCSE Physics 4.3 Hazards and uses of radioactive emissions and of background radiation, covering 4.3.1 Background radiation, 4.3.2 Different half-lives of radioactive isotopes, and 4.3.3 Uses of nuclear radiation. Each one has a worked solution and a mark scheme showing where the marks go.