This document provides information about the electromagnetic spectrum. It begins by asking questions about how waves in the electromagnetic spectrum differ and how each type is utilized. It then defines key terms like light, electromagnetic spectrum, and the different types of waves. It explains that light is a transverse wave that can travel without a medium. Frequency determines a wave's color/type, with higher frequencies having more energy. The electromagnetic spectrum includes radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. Each type of wave is then described in more detail along with common uses. Videos are provided for further explanation of infrared and the full electromagnetic spectrum.

1. Electromagnetic
Spectrum
Unit 9 - Light & Sound

2. Lesson 3: Questions
● How do the waves in the EM spectrum differ
from each other?
● How do we utilize each type of wave in the
EM spectrum?

3. Vocabulary
Define the following vocabulary words:
● Light
● Electromagnetic spectrum
● Radio waves
● Infrared
● Visible light
● Ultraviolet
● X-ray
● Gamma ray

4. Video: Electromagnetic Spectrum

5. Light
Light Energy - Energy that travels in the form
of waves.
○ Example: Sunlight

6. Light
Light - a transfer of energy that creates a
visual sensation
● Light is a transverse wave

7. Light
● Light does not need a medium to travel

8. Light
Frequency - the number of waves passing a
point per second
● Units: Hertz (Hz)
● Frequency describes the color/type of
light
HIGH frequency = Ex. UV Light Waves
LOW frequency = Ex. Radio Waves

9. Light
Light belongs to a larger category of waves
called the electromagnetic spectrum.
Electromagnetic spectrum - the full range of
visible and invisible waves.

10. Light
The electromagnetic spectrum includes:
● Radio waves
● Microwaves
● Infrared waves (IR)
● Visible light
● Ultraviolet waves (UV)
● X-Rays
● Gamma rays
All waves travel 300,000 km/s = SPEED OF LIGHT

11. Electromagnetic Spectrum
Wavelength
Frequency
Energy
Radio
(Microwaves, Radio, TV)
Infrared
(IR)
Ultraviolet
(UV)
X-Ray Gamma
Visible
Light
R
O Y G B I
V
Wavelength
Frequency
Energy
LONG
LOW
LOW
SHORT
HIGH
HIGH

12. Electromagnetic Spectrum
Radio Waves - used in radio and TV,
microwave ovens, and radar.
● Amplitude modulation (AM)
● Frequency modulation (FM)

13. Electromagnetic Spectrum
Microwaves - the shortest-wavelength radio
waves
● Cooking and reheating food
Radar Waves - waves reflect off objects and
return back towards the source they came from
● Doppler Effect
Television Waves - carry information for
pictures and sound

14. Electromagnetic Spectrum
Infrared Light (IR) - source of heat and used to
discover heat differences
● Warming lamps
● Thermograms

15. Electromagnetic Spectrum
Video: Infrared

16. Electromagnetic Spectrum
Visible Light - only light visible to humans
● Color (ROYGBIV)

17. Electromagnetic Spectrum
Ultraviolet Light - higher frequency than violet
● Sunlight (source of Vitamin D)
○ Excessive exposure damages skin
● Can disinfect air/bacteria

18. Electromagnetic Spectrum
X-Rays - makes pictures of the inside of solid
objects
● X-Ray technology

19. Electromagnetic Spectrum
Gamma Rays - high energy waves with the
greatest penetrating ability of all waves.
● Radiation therapy

20. Additional Video Resources
Click on the link below to view videos on each
of the electromagnetic spectrum waves.
Click here to learn more