Physics · Oct / Nov 2019 · Paper 12 · Question 39

Radioactive substances are used as tracers in medical examinations. A liquid tracer is injected into a patient. A detector 20 cm above the patient shows where the radioactive substance is in the body. What is the best radioactive substance to use?

1. Aan alpha-particle emitter with a half-life of a few hours
2. Ban alpha-particle emitter with a half-life of a few years
3. Ca gamma ray emitter with a half-life of a few hours
4. Da gamma ray emitter with a half-life of a few years

As printed in the paper