A radiation detector is placed on the bench in a laboratory. It detects a background count rate of 30 counts/minute.
State what is meant by background radiation. Suggest one source for it.
A sample containing atoms of the radioactive isotope carbon-14 is removed from a container and brought close to the detector. The average count rate increases to 750 counts/minute.
When a sheet of paper is placed between the sample and the detector, the average count rate falls slightly to 742 counts/minute. However, when a 5 mm thick plate of aluminum is placed between them, the average count rate returns to 30 counts/minute.
Carbon-14 is represented by the symbol 614C{}^{14}_{6}\text{C}614C. It decays to an isotope of nitrogen (N\text{N}N).
Deduce the type of radiation emitted by carbon-14. Explain your answer.
Write down the nuclide equation for the decay of carbon-14.
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.