Ionising electromagnetic radiation
I can explain the properties, uses and dangers of ionising electromagnetic radiation.
Ionising electromagnetic radiation
I can explain the properties, uses and dangers of ionising electromagnetic radiation.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- All EM waves can transfer energy, from a source to an absorber.
- Only UV, X-ray and gamma frequencies of EM wave cause ionisation. The higher the frequency, the more ionising.
- Ionising radiation can damage cells, cause genes to mutate and increase the risk of cancer.
- UV is used in lighting and to disinfect water. It causes tanning/sunburn. It increases the risk of skin cancer.
- X- and gamma rays are used in medical imaging. Gamma rays are used to kill cancer cells and to sterilise food/equipment.
Keywords
Energy transfer - Electromagnetic waves transfer energy because stores of energy decrease when they are emitted and increase when they are absorbed.
Ionisation - Ionisation is the process of an atom losing or gaining electrons so become charged/becoming an ion.
Ultraviolet - Ultraviolet means EM radiation with frequencies greater than visible light but lower than X–rays.
X-rays - X-rays are EM radiation with frequencies greater than ultraviolet but lower than gamma rays.
Gamma rays - Gamma rays are the highest frequency electromagnetic waves.
Common misconception
Gamma rays are always higher energy (or power), or more dangerous, than other frequencies of EM radiation.
EM waves transfer their energy in 'chunks' or 'packets'. The energy transferred by one 'packet' of radiation (and so its ionising ability) does depend on frequency. But the power of a beam of radiation depends on the intensity of the radiation too.
Content guidance
- Depiction or discussion of sensitive content
Supervision
Adult supervision recommended
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Starter quiz
6 Questions
have the lowest frequencies of any EM radiation.
have the highest frequencies of any EM radiation.
have frequencies higher than microwaves and lower than visible light.
negative
neutral
positive
Exit quiz
6 Questions
sunburn
destruction of cancer cells
heating of an object’s surface
heating of the water inside food
generation of electricity by a solar panel
detecting fake bank notes
scanning bags at security checks
sterilising medical equipment