Background radiation — AQA GCSE Physics
Test yourself on Background radiation with AQA GCSE practice questions.
7 days Premium · Then free forever · No card, no charge
Background radiation explained
Background radiation is the low level of ionising radiation present everywhere, all the time.
Read the full explanation
Most of it is natural. Radon gas seeps out of rocks, especially granite, and is breathed in; cosmic rays arrive from space and are partly absorbed by the atmosphere; there are naturally radioactive isotopes in soil, building materials, food and drink, and in our own bodies. A smaller share is man-made, chiefly fallout from nuclear weapons testing and from nuclear accidents, plus medical procedures and waste from the nuclear industry. Because it never switches off, every experiment with a source has to start by measuring the count rate with no source present and subtracting that background from every reading.
Your focus
- Name two natural and one man-made source of background radiation.
- Describe how a background count rate is measured and used to correct readings from a source.
- Interpret a count-rate against distance graph that levels off, identifying the level as background.
Background radiation exam tips
Marking Points
- one mark for background radiation being present all the time, from many sources around us
- one mark for two named natural sources, such as radon from rocks, cosmic rays from space, or food and drink
- one mark for a named man-made source, such as fallout from nuclear weapons testing or from a nuclear accident
- one mark for measuring the count rate with no source present and subtracting it from each reading
Examiner Tips
- 💡Check whether the question asks for natural or man-made sources, because a correct example from the wrong category scores nothing.
- 💡In range experiments, quote the background count rate as the level the readings fall back to; examiners look for that phrase.
- 💡Give a specific source, such as radon from granite, rather than a category like 'the environment'.
Common Mistakes
- listing only man-made sources and treating background radiation as pollution
- giving 'the Sun' as a source rather than cosmic rays from space
- claiming radon comes from nuclear power stations rather than from rocks
- forgetting the background correction, so the count rate appears not to fall to the expected level
- saying background radiation is zero indoors