(a(i))[1]
Define background radiation.
(a(ii))[1]
Suggest one source of radiation that may make a significant contribution to the background count rate.
(a(iii))[2]
Determine the count rate due to the tracer.
(b)[3]
Suggest which radioactive emission, alpha, beta or gamma, is suitable for detecting the leak in the water pipe. Explain your answer.
(c(i))[1]
Explain why the radioactive isotope must not have a very short half-life.
(c(ii))[1]
Explain why the radioactive isotope must not have a very long half-life.