An environmental engineer uses a radioactive tracer, Sodium-24, to detect a suspected leak in a deep underground water pipe.
Alpha (α\alphaα) radiation consists of:
A. high-speed electrons B. helium nuclei C. high-speed positrons D. electromagnetic waves
Define the term half-life of a radioactive isotope.
The engineer injects the Sodium-24 solution into the pipe and uses a detector at ground level to trace the emitted gamma rays. Suggest why an isotope that emits only beta-minus (β−\beta^-β−) radiation would be unsuitable for this application.
Sodium-24 has a half-life of 15 hours15\text{ hours}15 hours.
A sample of Sodium-24 has an initial activity of 640 MBq640\text{ MBq}640 MBq.
Explain why the activity of any radioactive sample reduces over time.
Calculate the activity of the Sodium-24 sample after 60 hours60\text{ hours}60 hours.
