1. Table of Contents The Nature of Electromagnetic Waves
Waves of the Electromagnetic Spectrum
Producing Visible Light
Wireless Communication

2. Electromagnetic Waves
The Nature of Electromagnetic Waves
Electromagnetic Waves
Believe it or not, you are being “showered” all the time, not by rain but by waves.

3. What Is an Electromagnetic Wave?
The Nature of Electromagnetic Waves
What Is an Electromagnetic Wave?
A transverse wave that transfers electrical and magnetic energy.
An electromagnetic wave travel as vibrations in electric and magnetic fields that move through space at the speed of light. (approximately 300,000 km/s)
They do NOT require a medium to travel through

4. Producing Electromagnetic Waves
Produced by charged particles.
When a charged particle moves, it produces a magnetic field.
When a charged particle changes its motion, its magnetic field changes. This causes the electric field to change.
The two fields are constantly causing each other to change.

5. All E.M waves travel at the same speed in a vacuum.
When they enter different mediums they will either speed up or slow down. (depending on the medium)

6. Models of Electromagnetic Waves
The Nature of Electromagnetic Waves
Models of Electromagnetic Waves
Many properties of electromagnetic waves can be explained by a wave model or a particle of light model. (photoelectric effect)
(Wave Model) Only some light waves pass through a polarizing filter. The light that passes through vibrates in only one direction and is called polarized light.

7. Electromagnetic Waves
The Nature of Electromagnetic Waves
Electromagnetic Waves
Click the Video button to watch a movie about electromagnetic waves.

8. End of Section: The Nature of Electromagnetic Waves

9. Discover Activity Think it over:
The band of colors shows the range of colors that makes up white light.

10. What Is the Electromagnetic Spectrum?
Waves of the Electromagnetic Spectrum
What Is the Electromagnetic Spectrum?
The electromagnetic spectrum is the complete range of electromagnetic waves placed in order of increasing frequency.
The electromagnetic spectrum is made up of radio waves, microwaves, infrared rays, visible light, ultraviolet light, x-rays, and gamma rays.

11. What Is the Electromagnetic Spectrum?
Waves of the Electromagnetic Spectrum
What Is the Electromagnetic Spectrum?
The electromagnetic spectrum is the complete range of electromagnetic waves placed in order of increasing frequency.
The electromagnetic spectrum is made up of radio waves, microwaves, infrared rays, visible light, ultraviolet light, x-rays, and gamma rays.

12. Electromagnetic Waves
Waves of the Electromagnetic Spectrum
Electromagnetic Waves
Electromagnetic waves are all around you–in your home, your neighborhood, and your town.

13. Electromagnetic Waves Activity
Waves of the Electromagnetic Spectrum
Electromagnetic Waves Activity
Click the Active Art button to open a browser window and access Active Art about electromagnetic waves.

14. The Nature of Electromagnetic Waves
Electric and magnetic Fields
300,000 km/s or 300,000,000 m/s
When a beam of light shines on some substances, it causes electrons in the substances to move (the photoelectric effect). If light did not have any of the properties of a stream of particles, this movement of electrons would not occur.
A polarizing filter allows only waves of light that vibrate in one direction to pass through. If two polarizing filters are placed so that one is rotated 90 degrees relative to the other, no light will pass through.
Electromagnetic radiation
Photoelectric effect
Photon
Polarized light
Electromagnetic wave

15. Waves of the Electromagnetic Spectrum
Radio Waves (or microwave)
Thermograms (or heating)
Killing Bacteria or producing vitamin D
X-rays
Gamma rays
The range of electromagnetic waves arranged in order of increasing frequency and wavelength.
Too much exposure can burn your skin, cause skin cancer, and damage your eyes.
It is an image in which the temperature of objects in indicated by different colors.
Radio Waves
Infrared rays make the skin feel warm

16. Electromagnetic Spectrum
Waves of the Electromagnetic Spectrum
Electromagnetic Spectrum
Click the Video button to watch a movie about the electromagnetic spectrum.

17. End of Section: Waves of the Electromagnetic Spectrum

18. Incandescent Lights Producing Visible Light
An incandescent light is a light bulb that glows when a filament inside it gets white hot.

19. Neon Lights Producing Visible Light
A neon light is a sealed glass tube that contains neon gas.

20. Comparing and Contrasting
Producing
Visible Light
Comparing and Contrasting
As you read, compare and contrast the five types of light bulbs by completing a table like the one below.
Ordinary Light Bulb
Tungsten-Halogen
Feature
Fluorescent
Vapor
Neon
Bulb Material
Glass
Quartz
Glass
Glass
Glass
Hot/Cool
Hot
Very Hot
Cool
Cool
Cool
Holes in data from book.
Tungsten filament and nitrogen gas and argon gas inside
Has tungsten filament and a halogen gas inside
Has neon or argon gas and solid sodium or mercury inside
Makeup
A gas and a powder coating inside
Has neon gas inside
More efficient than ordinary bulb
Efficiency
Not efficient
Very efficient
Very efficient
Very efficient

21. Data Sharing Lab Producing Visible Light
Click the PHSchool.com button for an activity about sharing data for the Consumer Lab Comparing Light Bulbs.

22. End of Section: Producing Visible Light

23. Radio and Television Wireless Communication
In AM transmissions, the amplitude of a radio wave is changed. In FM transmissions, the frequency is changed.

24. Cellular Phone System Wireless Communication
In the cellular phone system, cellular phones transmit and receive radio waves that travel to the nearest tower.

25. Communication Satellites
Wireless
Communication
Communication Satellites
In the Global Positioning System (GPS), signals from four satellites are used to pinpoint a location on Earth.

26. Using Prior Knowledge Wireless Communication
Your prior knowledge is what you know before you read about a topic. Before you read, write what you know about wireless communication in a graphic organizer like the one below. As you read, continue to write what you learn.
What You Know
Cellular phones don’t use wires.
Radio and television signals travel through the air.
What You Learned
The signals for radio and television programs are carried by radio waves.
The signals can be transmitted by changing either the amplitude or the frequency of the radio waves.
Cellular phones transmit and receive signals using microwaves.

27. Links on Using Waves to Communicate
Wireless
Communication
Links on Using Waves to Communicate
Click the SciLinks button for links on using waves to communicate.

28. End of Section: Wireless Communication

29. Electromagnetic waves
Graphic Organizer
Electromagnetic waves
travel at the speed of
consist of
have different
Magnetic fields
Electric fields
Wavelengths
Frequencies
Light

30. End of Section: Graphic Organizer