Uses & Dangers of Radiation Practice Questions

Which type of radiation is emitted by the source in an ionisation smoke alarm?

A alpha

B beta minus

C gamma

D X-ray

Explain why a source that emits gamma radiation would not work in this smoke alarm.

The source in the alarm has a half-life of 432 years. Explain why a source with such a long half-life is used.

Explain why a gamma source is used to sterilise the instruments, rather than an alpha source.

Give one advantage of sealing the instruments in packets before they are irradiated.

State why the instruments are not radioactive after they have been treated.

State two precautions the teacher should take to reduce the radiation dose received by the students.

The teacher always uses long-handled tongs to move the source. Explain why.

The source used emits beta radiation. Explain why a beta source is used, rather than an alpha source or a gamma source.

The source chosen has a half-life of about 29 years. Explain why a source with a long half-life is needed for this job.

State what happens to the reading at the detector if the foil becomes too thick, and what the control unit must do.

Explain why the tracer chosen must be a gamma emitter.

The tracer used has a half-life of about 6 hours. Explain why this half-life is suitable.

Describe how the engineers use the detector to find the position of the leak.

Explain how the carbon-11 tracer allows an image of the patient's brain to be produced.

A hospital that offers PET scans must have its own cyclotron on site to make the carbon-11. Explain why.

Give two sources of the radiation detected when there was no sample near the tube.

Calculate the count rate from the granite, corrected for background radiation. Give your answer in counts per minute.

The student repeats each measurement three times and calculates a mean. Explain why this is good practice.

Explain the difference between irradiation and contamination.

One of the liquids contains an alpha-emitting isotope. Explain why swallowing a small amount of this liquid would be far more hazardous than standing 1 m away from the same, sealed, alpha source.

Explain why the gamma source in Treatment B is rotated around the patient.

Compare Treatment A and Treatment B as ways of treating this tumour.

An isotope is to be injected into a patient's bloodstream as a tracer, so that a scanner outside the body can check the blood flow through the liver. The scan takes about 40 minutes. Choose the most suitable isotope and justify your choice.

A factory needs a source to sterilise pre-packed medical dressings, hour after hour, for many years. Choose the most suitable isotope and justify your choice.

Explain why exposure to ionising radiation can be dangerous to living cells.