Starter quiz
- Which of the following happens when a wave is transmitted by a medium?
- The wave bounces off the medium.
- The wave passes through the medium. ✓
- The wave’s energy is absorbed by the medium.
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- The ______ of a wave is the number of wavelengths passing a point each second.
- 'frequency' ✓
- Which of the following are examples of ionisation?
- A neutral atom gains a proton.
- A neutral atom loses two protons.
- An neutral atom loses an electron. ✓
- A neutral atom gains two electrons. ✓
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- Which of the following type of electromagnetic radiation has the longest wavelengths?
- X–rays
- radio waves ✓
- light waves
- infrared waves
- microwaves
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- Which of the following types of electromagnetic radiation can cause ionisation?
- radio waves
- gamma rays ✓
- ultraviolet waves ✓
- microwaves
- infrared waves
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- Why are some types of electromagnetic radiation more ionising than others?
- At longer wavelengths, there is more energy per ‘packet’ of radiation.
- At higher frequencies, there is more energy per ‘packet’ of radiation. ✓
- At shorter wavelengths, there is less energy per ‘packet’ of radiation.
- At lower frequencies, there is more energy per ‘packet’ of radiation.
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Exit quiz
- Some types of electromagnetic radiation are non–ionising. Which of the following statements about non–ionising radiations are correct?
- It includes X-rays.
- It includes infrared waves. ✓
- It includes gamma rays.
- It cannot change the number of electrons an atom has. ✓
- It does not cause atoms to become ions. ✓
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- Which of the following types of radiation are used to cook food?
- infrared radiation ✓
- microwaves ✓
- radio waves
- visible light
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- Which of the following type of radiation is used to communicate between Earth and satellites?
- infrared radiation
- ultraviolet radiation
- microwaves ✓
- light waves
- X–rays
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- Four types of electromagnetic radiation are: radio waves, microwaves, infrared waves, visible light. How many of these can harm humans, if the intensity is high enough?
- none of these
- one
- two
- three
- four ✓
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- Lower frequency radio waves and higher frequency radio waves can both be used for long-distance communication. Which of the following describe features of lower frequency radio waves?
- They can bend around large objects, such as hills. ✓
- The direction in which they travel cannot be changed.
- They do not pass through the ionosphere. ✓
- They can pass through the ionosphere.
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- Which of the following statements are correct?
- Radio waves can pass through buildings. ✓
- Visible or infrared waves can transmit information along optical fibres. ✓
- Infrared radiation can transmit more deeply into food than microwaves can.
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Worksheet
Presentation
Video
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 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.
Antenna - An antenna is a metal structure designed to emit or absorb electromagnetic waves.