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.
120 exam-style questions on CIE IGCSE Physics 5.2.3a Radioactive decay. Each one has a worked solution and a mark scheme showing where the marks go.