AQA GCSE Physics (8463), Higher tier · Atomic structure › Hazards and uses of radiation
Practise Background radiation. 11 exam-style questions on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
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Background radiation is around us all of the time. Give two natural sources of background radiation.
Rocks (and the radon gas released from them) and cosmic rays.
Suggest why the dose from cosmic rays is higher at the height at which aircraft fly than at ground level.
There is less air above to absorb the cosmic rays.
Sample questions
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy4 marks
Background radiation is around us all of the time.
(a) Give two natural sources of background radiation.[2]
(b) Give one man-made source of background radiation.[1]
(c) Radiation dose is measured in sieverts (Sv). 1000 millisieverts (mSv) = 1 sievert (Sv) The average annual radiation dose for a person in the UK is about 2.7 mSv. Give 2.7 mSv in sieverts.[1]
Show the answer and mark scheme
(a)Answer: Rocks (and the radon gas released from them) and cosmic rays.
rocks / the ground / building materials
cosmic rays (from space)
radon gas (from rocks)
food and drink / radioactive isotopes inside our bodies
(b)Answer: Fallout from nuclear weapons testing.
fallout from nuclear weapons testing
nuclear accidents
medical uses of radiation (e.g. X-rays)
waste / discharges from the nuclear industry
(c)Answer: 0.0027 Sv
0.0027 (Sv)
Question 2Medium5 marks
Airline pilots receive a higher dose of radiation than most people. At the height at which aircraft fly, the dose from cosmic rays is about 0.005 mSv per hour.
(a) Suggest why the dose from cosmic rays is higher at the height at which aircraft fly than at ground level.[1]
(b) A pilot flies for 700 hours in one year. Calculate the dose from cosmic rays that the pilot receives while flying in that year.[2]
(c) Give one other occupation in which a person may receive a higher radiation dose than average.[1]
(d) The annual dose limit for people who work with radiation is 20 mSv. The average annual dose from background radiation is 2.7 mSv. Explain whether the pilot's dose is a cause for concern.[1]
Show the answer and mark scheme
(a)Answer: There is less air above to absorb the cosmic rays.
there is less atmosphere above the aircraft to absorb the cosmic rays
(b)Answer: 3.5 mSv
700 × 0.005
3.5 (mSv)
(c)Answer: A radiographer in a hospital.
hospital worker using radiation / radiographer
nuclear power station worker
miner
astronaut
(d)Answer: Not a major concern: about 6.2 mSv a year in total, well below the 20 mSv limit.
no: the total of about 6.2 mSv (3.5 + 2.7) is well below the 20 mSv limit (although any dose slightly increases the risk)
Question 3Hard8 marks
Radon is a radioactive gas that seeps into homes from rocks in the ground. The radon concentration in a home is measured in Bq/m3, the activity of the radon in each cubic metre of air. In this question, assume that each 1 Bq/m3 of radon gives a person living in the home an annual dose of 0.050 mSv.
(a) The radon concentration in a house is 480 Bq/m3. Calculate the annual dose from radon for a person living in the house.[1]
(b) A fan system is fitted that reduces the radon concentration by 75%. Calculate the reduction in the annual dose.[2]
(c) Homes with a radon concentration above 200 Bq/m3 are advised to take action. Calculate the minimum percentage reduction needed to bring this house down to 200 Bq/m3. Give your answer to 2 significant figures.[2]
(d) Radon emits alpha particles. Explain why radon in a home is a hazard, even though alpha particles cannot pass through skin.[3]
(d)Answer: Radon is breathed in, so the alpha particles are emitted inside the lungs next to living cells, where their strong ionisation damages the cells.
radon gas is breathed in, so the radioactive atoms get inside the lungs (contamination)
the alpha particles are emitted inside the lungs, right next to living cells
alpha particles are strongly ionising, so they damage the cells (and can cause lung cancer)