4Wave-8
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Contents
Outcomes
- Pupils can identify the sections of the electromagnetic spectrum.
- Pupils can identify the uses and dangers of sections of the electromagnetic spectrum.
Specification References
- 3.10 understand that light is part of a continuous electromagnetic spectrum which includes radio, microwave, infrared, visible, ultraviolet, x-ray and gamma ray radiations and that all these waves travel at the same speed in free space
- 3.11 recall the order of the electromagnetic spectrum in decreasing wavelength and increasing frequency, including the colours of the visible spectrum
- 3.12 recall some of the uses of electromagnetic radiations:
- 3.13 recall the detrimental effects of excessive exposure of the human body to electromagnetic waves:
Starter
Mini whiteboards put the 7 parts of the EM spectrum in order of increasing frequency
Main Body of Lesson
Ensure that pupils have the following information:
Uses
- Radio - communication
- Microwave - communication, energy transfer (e.g. microwave oven, solar satellite)
- Infrared - thermal energy transfer, night vision
- Visible
- Ultraviolet - sterilisation, tanning,
- X-ray - medical (diagnosis), x-ray diffraction (crystallography)
- Gamma ray - sterilisation, medical (treatment)
Dangers
- Radio - negligible hazard (possibly KISS FM)
- Microwave - negligible hazard, internal heating
- Infrared - surface heating
- Visible
- Ultraviolet - blindness, sunburn
- X-ray - blindness, cancers (mutation)
- Gamma ray - blindness, cancers (mutation)
Give a series of frequencies and wavelengths and have pupils calculate the missing value. Also ensures that they are aware to use the speed of light in a vacuum if they aren't given a speed. Here is a selection of values you could use.
Homework
- This topic is ideal poster work. Could make a very nice display.
Additional Information
Resources Required
Textbook References
- Pople 7.11 pp. 160-163