1. Uses of Radioisotopes

2. Tracers
A tiny amount of a radioactive isotope can be used to track the movement of a chemical – rather like a barcode or a luggage label!

3. Medical Tracers
A chemical ‘tagged’ with a tiny amount of radioisotope is injected into the body.
Its progress through the body can be detected using a sensitive gamma camera.
So you can see if the organs are processing the chemicals correctly.

4. Industrial Tracers
Small amounts of radioactive substance can be allowed to flow along a leaky pipeline.
The reading from a G-M counter will rise as you pass the point where there is a leak.

5. Radioactive Monitoring
Changes near a radioactive source alter its effects.
Smoke detectors use a weak alpha source to produce ionisation and a small current.
Smoke absorbs the radiation and the current drops – triggering an alarm.

6. Radioactive Monitoring
A radioisotope can be used to monitor and control the thickness of paper/ plastic/ thin metal foil.
A gamma source can be used to produce a picture (like an X-ray) of a jet engine to look for developing cracks.

7. Sterilisation High doses of radiation can kill tiny bacteria.
So syringes, bandages etc. in sealed packages will remain sterile.
Irradiated food supplies will keep fresh for longer.

8. Radiotherapy
Gamma rays (or high-energy X-rays) can be used to shrink/ destroy tumours.
The rapidly-dividing cancer cells are more susceptible to damage from ionising radiation than normal cells.

9. Radioactive dating
Carbon dating looks at how much C-14 there is left in a once-living object. Its age can then be worked out because we know the half-life of C-14.
Other radioactive substances can be used to date rocks.