Ionising electromagnetic radiation
Lesson details
Learning outcome
I can explain the properties, uses and dangers of ionising electromagnetic radiation.
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.
Teacher tip
Students need to understand in what sense gamma rays transfer most energy (since more intense lower freq. radiation can have greater power). This lesson describes gamma as transferring more energy per 'chunk' or 'packet' of radiation rather than per each 'ray' or 'wave' which is less accurate/clear.
Content guidance
Depiction or discussion of sensitive content
Supervision
Adult supervision recommended
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Electromagnetic radiation that has longer wavelengths than X–rays and shorter wavelengths than light is called radiation.
Q2.Match the following types of electromagetic radiation to the correct description.
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.
Q3.Which of the following statements about electromagnetic waves are correct?
Q4.Which of the following types of particle is found outside the nucleus of an atom?
Q5.Match each of the following types of particle with its type of electric charge.
negative
neutral
positive
Q6.An atom contains 6 protons, 5 neutrons and 6 electrons. What is the overall electric charge on the atom?
Assessment exit quiz
6 Questions
Q1.Electromagnetic (EM) radiation can transfer energy to objects.
Match each of the following types of EM radiation with an effect that can occur when it transfers energy.
sunburn
destruction of cancer cells
heating of an object’s surface
heating of the water inside food
generation of electricity by a solar panel
Q2.Some types of electromagnetic radiation can make an atom gain or lose one or more electrons and become charged.
A charged atom is called an ...
Q3.Which of the following is the most strongly ionising type of electromagnetic radiation?
Q4.Which of the following increases the potential harm when electromagnetic radiation hits a living organism?
Q5.Which of the following can happen when an atom absorbs radiation?
Q6.Match each of the following types of electromagnetic radiation to one of its uses.
detecting fake bank notes
scanning bags at security checks
sterilising medical equipment
To help you plan your 11 combined science lesson on: Ionising electromagnetic radiation, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 11 combined science 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 combined science lessons from the Electromagnetic waves unit, dive into the full secondary combined science curriculum, or learn more about lesson planning.