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?
An electromagnetic wave consists of vibrating electric and magnetic fields that move through space at the speed of light.

4. 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. Only some light waves pass through a polarizing filter. The light that passes through vibrates in only one direction and is called polarized light.

5. Outlining The Nature of Electromagnetic Waves
An outline shows the relationship between main ideas and supporting ideas. As you read, make an outline about electromagnetic waves. Use the red headings for the main ideas and the blue headings for the supporting ideas.
The Nature of Electromagnetic Waves
What Is an Electromagnetic Wave?
Producing Electromagnetic Waves
Energy
Speed
Models of Electromagnetic Waves
Wave Model of Light
Particle Model of Light

6. Links on the Nature of Waves
The Nature of Electromagnetic Waves
Links on the Nature of Waves
Click the SciLinks button for links on the nature of waves.

7. End of Section: The Nature of Electromagnetic Waves

8. 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.

9. Scientific Notation Waves of the Electromagnetic Spectrum
Frequencies of waves often are written in scientific notation. A number in scientific notation consists of a number between 1 and 10 that is multiplied by a power of 10. To write 150,000 Hz in scientific notation, move the decimal point left to make a number between 1 and 10:
In this case, the number is 1.5. The power of 10 is the number of spaces you moved the decimal point. In this case, it moved 5 places:
150,000 Hz = 1.5 X 105 Hz

10. Scientific Notation Waves of the Electromagnetic Spectrum
Practice Problem
A radio wave has a frequency of 5,000,000 Hz. Write this number in scientific notation.
5.0 X 106 Hz

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

12. The Electromagnetic Spectrum
Waves of the Electromagnetic Spectrum
Previewing Visuals
Before you read, preview Figure 3. Then write two questions that you have about the diagram in a graphic organizer like the one below. As you read, answer your questions.
The Electromagnetic Spectrum
Q. Which electromagnetic waves have the shortest wavelength?
A. Gamma rays have the shortest wavelength.
Q. Which electromagnetic waves have the lowest frequency?
A. Radio waves have the lowest frequency.

13. End of Section: Waves of the Electromagnetic Spectrum

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

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

16. 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

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

18. End of Section: Producing Visible Light

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

20. Comparing Frequencies
Wireless
Communication
Comparing Frequencies
The table shows the ranges of radio broadcast frequencies used for AM radio, UHF television, FM radio, and VHF television.

21. Comparing Frequencies
Wireless
Communication
Comparing Frequencies
Interpreting Data:
In the table, what units of measurement are used for frequency?
Kilohertz (kHz) and megahertz (MHz)

22. Comparing Frequencies
Wireless
Communication
Comparing Frequencies
Interpreting Data:
Which type of broadcast shown in the table uses the highest frequency radio waves? Which uses the lowest frequency waves?
UHF television uses the highest frequency radio waves, and AM radio broadcast uses the lowest frequency radio waves.

23. Comparing Frequencies
Wireless
Communication
Comparing Frequencies
Calculating:
Which type of broadcast uses waves with the shortest wavelength?
UHF television uses waves with the highest frequency and therefore the shortest wavelength.

24. Comparing Frequencies
Wireless
Communication
Comparing Frequencies
Inferring:
A broadcast uses a frequency of 100 MHz. Can you tell from this data if it is a television or radio program? Explain.
You cannot tell from this data if it is a television or radio program, because VHF television and FM radio both broadcast radio waves with a frequency of 100 MHz.

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

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

27. 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.

28. 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.

29. End of Section: Wireless Communication

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

31. End of Section: Graphic Organizer