1.1. Radioactivity is used in PET scanners in hospitals.

PET scanners are used to diagnose cancer.

State two precautions that hospital staff might take when working with radioactivity.

1.2. State two other uses of radioactivity, apart from treatment or diagnosis of cancer.

1.3. The diagram shows a machine which makes aluminium foil.

The machine uses a radioactive source to measure the thickness of the foil.  

The radioactive source emits beta particles. The output from the detector indicates the thickness of the foil.

Complete the following sentences by highlighting the correct answer. 

If the aluminium foil gets too thin, the count rate at the detector increases / decreases. 

This sends a signal to a computer to push the rollers closer together / further apart.

Beta particles are used because they can / cannot pass through a sheet of aluminium which is more than a few millimetres thick.

1.4. Give two reasons why gamma is the most suitable type of radiation for sterilising medical equipment.