Uses & Dangers of Radiation (Edexcel GCSE Combined Science: Physics): Flashcards
Exam code: 1SC0
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Define dose.
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Cards in this collection (15)
Define dose.
The amount of radiation received by a person, measured in sieverts (Sv).
What is a dosimeter?
A device that measures the amount of radiation a person is exposed to, often worn by radiographers or others working with radiation.
How can ionising radiation lead to cancer?
It can ionise atoms in DNA, damaging the strand. If the DNA is repaired incorrectly it may mutate, and a mutated cell that replicates itself can form a tumour.
State two acute effects of radiation exposure on the body.
Skin burns, similar to severe sunburn, and a reduction in white blood cells, which increases susceptibility to infection.
Why can radiation used to treat cancer also damage healthy tissue?
High-energy radiation such as gamma rays and X-rays can damage healthy tissue if it is not properly targeted at the tumour.
State three ways of handling a radioactive source safely.
Any three from: keep it in a shielded container (e.g. lead-lined box) when not in use; use gloves and tongs; wear protective clothing; limit the time it is used for.
A person in the UK normally receives a dose of about 3 mSv of radiation per year. This is due to _____ radiation.
A person in the UK normally receives a dose of about 3 mSv of radiation per year. This is due to background radiation.
True or False?
A person is exposed to more radiation during a dental X-ray than during a transatlantic flight.
False.
A person is exposed to 0.005 mSv of radiation during a dental X-ray compared to 0.8 mSv of radiation during a transatlantic flight.
Therefore, a person is exposed to 160 times more radiation during a transatlantic flight than during a dental X-ray.
Define contamination.
The unwanted presence of materials containing radioactive atoms on other materials.
Define irradiation.
The process of exposing a material to alpha, beta or gamma radiation. It does not make the material radioactive.
Why is contamination generally more dangerous than irradiation?
Contamination causes continuous exposure to radiation as the radioactive atoms remain in place, and is especially dangerous if a source gets inside the body, where it irradiates internal organs as it moves through.
State one way of protecting against irradiation and one way of protecting against contamination.
Irradiation: lead-lined suits/shielding absorb the radiation.
Contamination: an airtight suit stops radioactive atoms getting inside the body.
Why does a source with a short half-life pose a greater risk of irradiation?
A short half-life means the source has a high activity, so there is a high rate of radioactive emissions compared with a long half-life source.
A source with a long half-life poses a greater risk of ______ because it remains radioactive for a long time.
A source with a long half-life poses a greater risk of contamination because it remains radioactive for a long time.
True or False?
Irradiating a piece of surgical equipment makes it radioactive.
False.
Irradiation does not make a material radioactive; only contamination, where radioactive atoms get onto or into a material, does this.
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