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.
To help you plan your year 11 physics lesson on: Ionising electromagnetic radiation, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 11 physics lesson on: Ionising electromagnetic radiation, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 4 physics lessons from the Electromagnetic waves unit, dive into the full secondary physics curriculum, or learn more about lesson planning.
Content guidance
- Depiction or discussion of sensitive content
Supervision
Adult supervision recommended
Licence
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