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

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Page 1: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

The Nature of Electromagnetic Waves

Waves of the Electromagnetic Spectrum

Producing Visible Light

Wireless Communication

Table of Contents

Page 2: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum The Nature of Electromagnetic Waves

Electromagnetic Waves

Believe it or not, you are being “showered” all the time, not by rain but by waves.

Page 3: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum 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.

Page 4: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum 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.

Page 5: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

OutliningAn 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

The Nature of Electromagnetic Waves

I. What Is an Electromagnetic Wave?A. Producing Electromagnetic

WavesB. EnergyC. Speed

II. Models of Electromagnetic WavesA. Wave Model of LightB. Particle Model of Light

Page 6: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

Links on the Nature of Waves

Click the SciLinks button for links on the nature of waves.

The Nature of Electromagnetic Waves

Page 7: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

End of Section:The Nature of

Electromagnetic Waves

Page 8: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

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.

Page 9: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

Scientific NotationFrequencies 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

Waves of the Electromagnetic Spectrum

Page 10: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

Scientific Notation

Practice Problem

A radio wave has a frequency of 5,000,000 Hz. Write this number in scientific notation.

5.0 X 106 Hz

Waves of the Electromagnetic Spectrum

Page 11: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

Electromagnetic Waves

Electromagnetic waves are all around you–in your home, your neighborhood, and your town.

Waves of the Electromagnetic Spectrum

Page 12: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

Previewing VisualsBefore 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.

Waves of the Electromagnetic Spectrum

Page 13: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

End of Section:Waves of the

Electromagnetic Spectrum

Page 14: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum ProducingVisible Light

Incandescent Lights

An incandescent light is a light bulb that glows when a filament inside it gets white hot.

Page 15: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum ProducingVisible Light

Neon Lights

A neon light is a sealed glass tube that contains neon gas.

Page 16: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

Feature

Comparing and ContrastingAs you read, compare and contrast the five types of light bulbs by completing a table like the one below.

Glass

Ordinary Light Bulb

Tungsten-Halogen

Fluorescent Vapor Neon

Bulb Material

Hot/Cool

Makeup

Efficiency

Quartz Glass Glass

Hot Very Hot Cool

Tungsten filament and nitrogen gas and argon gas inside

Has tungsten filament and a halogen gas inside

A gas and a powder coating inside

Has neon or argon gas and solid sodium or mercury inside

Has neon gas inside

Not efficient More efficient than ordinary bulb

Very efficient Very efficient

ProducingVisible Light

Glass

Cool Cool

Very efficient

Page 17: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

Data Sharing Lab

Click the PHSchool.com button for an activity about sharing data for the Consumer Lab Comparing Light Bulbs.

ProducingVisible Light

Page 18: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

End of Section:Producing

Visible Light

Page 19: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum WirelessCommunication

Radio and Television

In AM transmissions, the amplitude of a radio wave is changed. In FM transmissions, the frequency is changed.

Page 20: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

Comparing Frequencies

The table shows the ranges of radio broadcast frequencies used for AM radio, UHF television, FM radio, and VHF television.

WirelessCommunication

Page 21: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

Comparing Frequencies

Kilohertz (kHz) and megahertz (MHz)

Interpreting Data:

In the table, what units of measurement are used for frequency?

WirelessCommunication

Page 22: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

Comparing Frequencies

UHF television uses the highest frequency radio waves, and AM radio broadcast uses the lowest frequency radio waves.

Interpreting Data:

Which type of broadcast shown in the table uses the highest frequency radio waves? Which uses the lowest frequency waves?

WirelessCommunication

Page 23: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

Comparing Frequencies

UHF television uses waves with the highest frequency and therefore the shortest wavelength.

Calculating:

Which type of broadcast uses waves with the shortest wavelength?

WirelessCommunication

Page 24: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

Comparing Frequencies

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.

Inferring:

A broadcast uses a frequency of 100 MHz. Can you tell from this data if it is a television or radio program? Explain.

WirelessCommunication

Page 25: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum WirelessCommunication

Cellular Phone System

In the cellular phone system, cellular phones transmit and receive radio waves that travel to the nearest tower.

Page 26: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum WirelessCommunication

Communication Satellites

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

Page 27: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

What You Know

What You Learned

Using Prior KnowledgeYour 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.

1. Cellular phones don’t use wires.2. Radio and television signals travel through the air.

1. The signals for radio and television programs are carried by radio waves.

2. The signals can be transmitted by changing either the amplitude or the frequency of the radio waves.

3. Cellular phones transmit and receive signals using microwaves.

WirelessCommunication

Page 28: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

Links on Using Waves to Communicate

Click the SciLinks button for links onusing waves to communicate.

WirelessCommunication

Page 29: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

End of Section:Wireless

Communication

Page 30: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

Graphic Organizer

Magnetic fields

Electromagnetic waves

consist of travel at the speed of

have different

Electric fields Wavelengths

Light

Frequencies

Page 31: The Electromagnetic Spectrum The Nature of Electromagnetic Waves Waves of the Electromagnetic Spectrum Producing Visible Light Wireless Communication Table

The Electromagnetic Spectrum

End of Section:Graphic Organizer