Non-ionising electromagnetic radiations
I can explain the properties, uses and dangers of non–ionising electromagnetic radiation.
Non-ionising electromagnetic radiations
I can explain the properties, uses and dangers of non–ionising electromagnetic radiation.
Lesson details
Key learning points
- Radio waves, microwaves, IR and visible light are non–ionising EM radiation. They can harm cells by heating.
- Radio waves are produced by oscillations of current. When absorbed, they may produce oscillations of current.
- Radio waves and microwaves are used for long distance communication, broadcasting and data transmission.
- Microwaves are absorbed by water, so can be used to cook food from within. IR radiation cooks the surface of food.
- IR is used for heating and thermal imaging. Visible light and IR are used for data transmission in optical fibres.
Common misconception
The majority of pupils struggle to differentiate between ionising and non–ionising radiation.
Explicitly teach that non–ionising radiation is not able to force electrons off atoms – it cannot turn atoms into ions. What it may be able to do is cause heating by increasing the movement of particles and therefore temperature of the substance.
Keywords
Frequency - The frequency of a wave means the number of oscillations occurring per second, which is the same as the number of waves arriving per second.
Non-ionising - Radio waves, microwaves, infrared and visible light are non–ionising electromagnetic waves, as they cannot remove electrons from atoms.
Heating - Any process that transfers energy because of a temperature difference, or causes a temperature rise, can be called heating.
Oscillations - Oscillations are the vibrations of a wave about a rest position.
Antenna - An antenna is a metal structure designed to emit or absorb electromagnetic waves.
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).
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