electromagnetic spectrum, sound vs light,

1. 6.6 Electromagnetic Waves
29 January 2015
Think about:
• How well behaved you are
• How good you are at science
• How much you like chocolate hob
nobs

2. Aims
• Describe visible light as part of the
electromagnetic spectrum
• State other types of radiation

8. Electromagnetic waves

9. Travel through empty space

10. Travel at 300 000 km/s

11. Transverse waves

12. They transfer energy

13. Light vs Sound
Example of wave
LIGHT SOUND
Type of wave
Speed in air /
km/s
Material of
medium

14. Light vs Sound
Example of wave
LIGHT SOUND
Type of wave Transverse Longitudinal
Speed in air /
km/s
300 000 340
Material of
medium
No material
required
Solid, liquid, gas

15. Example of wave
LIGHT SOUND
Type of wave
Speed in air /
km/s
Material of
medium
Example of wave
LIGHT SOUND
Type of wave
Speed in air /
km/s
Material of
medium

16. Electromagnetic radiation
actually comes in packets
or lumps. I call these
packets ‘quanta’. A quanta
of light is called a photon.
Nobel prize please…

17. The higher the frequency, the more
energy the photon has

18. Intensity
Energy of each photon
Number of photons arriving each second

19. The electromagnetic spectrum

23. Radio waves

24. Radiowaves
• Communications: TV, mobile phones, local
radio, police

25. Microwaves

26. Microwaves
• Microwaves ovens, communicating with
satellites, RADAR

27. Infrared

28. Infra-red
• Search and rescue teams, detect circulation
problems, (cancer, arthritis), astronomy,
burglar alarms

29. Light

30. Ultraviolet

31. UV
• Produce vitamin D in our skin, suntan, skin
cancer

32. X-rays

33. X-rays
• X-rays (bones, teeth), check welds and joints,
food

34. Gamma rays

35. Gamma rays
• Make Hulks, sterilise food and utensils,
tracers, radiotherapy

36. RECALL THE DETRIMENTAL EFFECTS OF
EXCESSIVE EXPOSURE OF THE HUMAN
BODY TO ELECTROMAGNETIC WAVES
3.13

42. Make an EM spectrum booklet
Guest starring Mr. Simon Porter

59. The EM spectrum
• You now have seven sections to fill in with
information regarding the seven types of
electromagnetic radiation
• Include uses, dangers, detectors, examples
and origins if you can
• The better you make it the better it will help
your revision