Latest revision as of 14:55, 30 October 2011

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

Website References

Skills Addressed

Safety/Hazards

Notes