A radioactive material, YYY, has a half-life of 3 minutes. At the beginning of an experiment, a sample of the material produces a count-rate of 640 counts/s.
Determine the expected count-rates from this sample at: (i) t=6t = 6t=6 minutes, (ii) t=15t = 15t=15 minutes.
Using the radioactive decay relationship: (i) Calculate the expected count-rate from the sample after 7.5 minutes. (ii) Find the time it takes for the count-rate of the sample to fall from 500 counts/s to 250 counts/s.
A second sample of this same radioactive material YYY gives an initial count-rate of 320 counts/s. What is the half-life of this second sample?
To track the flow of water in deep underground pipelines and locate leaks, a radioactive isotope is added to the water. (i) Explain why the radioactive material YYY is not suitable for this application. (ii) State two other properties (excluding half-life) that a radioactive material must have to be suitable for detecting leaks in underground pipelines.
144 exam-style questions on CIE IGCSE Physics 5.2.4a Half-life. Each one has a worked solution and a mark scheme showing where the marks go.