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

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.

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

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.

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)

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.

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

End of Section: The Nature of Electromagnetic Waves

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

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.

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.

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

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.

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

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

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

End of Section: Waves of the Electromagnetic Spectrum

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

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

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

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

End of Section: Producing Visible Light

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

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

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

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.

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.

End of Section: Wireless Communication

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

End of Section: Graphic Organizer