Kathleen Connors - Light and Color

A LOOK AT PHYSICAL SCIENCE

LIGHT AND COLOR

KATHLEEN CONNORS

A LOOK AT PHYSICAL SCIENCE

LIGHT AND

COLOR

BY KATHLEEN CONNORS

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Cataloging-in-Publication Data

Names: Connors, Kathleen. Title: Light and color / Kathleen Connors. Description: New York : Gareth Stevens Publishing, 2019. | Series: A look at physical science | Includes index. Identifiers: LCCN ISBN 9781538221532 ( pbk. ) | ISBN 9781538221518 ( library bound) | ISBN 9781538221549 ( pack) Subjects: LCSH: Light--Juvenile literature. | Color--Juvenile literature. Classification: LCC QC360. C645 2019 | DDC 535--dc23

First Edition

Published in 2019 by Gareth Stevens Publishing East 14th Street, Suite New York, NY 10003

Copyright 2019 Gareth Stevens Publishing

Designer: Samantha DeMartin Editor: Kristen Nelson

Photo credits: Series art Creative Mood/Shutterstock. com; cover, p. Pavel_Klimenko/ Shutterstock. com; p. ( lamp) Lijphoto/Shutterstock. com; p. ( flame) MICROSONE/ Shutterstock. com; p. ( flashlight) MargoLev/Shutterstock. com; p. ( christmas lights) FoapAB/ Shutterstock. com; p. oorka/Shutterstock. com; p. Designua/Shutterstock. com; p. Happy Stock Photo/Shutterstock. com; p. ferocioussnork/Shutterstock. com; p. Praphan Jampala/ Shutterstock. com; p. AHonaker/Shutterstock. com; p. ( transparent) wavebreakmedia/ Shutterstock. com; p ( translucent) SOLOTU/Shutterstock. com; p. ( opaque) joloei/ Shutterstock. com; p. Ray B Stone/Shutterstock. com; p. ( both) GIPhotoStock/ Science Source/Getty Images; p. ( top) Yana Alisovna/Shutterstock. com; p. ( bottom) mikeshinmaksim/Shutterstock. com; p. Pressmaster/Shutterstock. com; p. piyaphong/ Shutterstock. com; p. ( rainbow) EGOR_21/Shutterstock. com; p. ( prism) Pro Symbols/ Shutterstock. com; p. ( eye) browndogstudios/Shutterstock. com.

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CONTENTS

All the Light We Can See Whats Light? Heat Makes Light Frequency Is Color Got White? Reflection Passing Through Refraction A Rainbow! Seeing In Color Light and Color Basics Glossary For More Information Index

Words in the glossary appear in bold type the first time they are used in the text

ALL THE LIGHT WE CAN SEE

The light from a lamp or flashlight is visible light, or the light people can see. There are also other kinds of light people cant see. All light is electromagnetic radiation. Radiation is energy that moves and spreads out as it moves.

MAKE THE GRADE

Visible light is one small part of the electromagnetic spectrum.

WHATS LIGHT?

Light is made up of tiny particles called photons. The movement of electrons creates photons. Sometimes, an electron gains energy and it moves to a higher place, or orbital, in an atom. When it falls back down, it gives off a photon.

MAKE THE GRADE

Electrons are the negatively charged parts of an atom.

NUCLEUS

ORBITAL ELECTRONS

Light moves through space as a wave. A wave is something that travels through space and matter, moving energy from one place to another. Light, which is part of the electromagnetic spectrum, can have short or long wavelengths.

MAKE THE GRADE

Gamma rays have the shortest wavelengths on the electromagnetic spectrum. Radio waves have the longest. Visible light is in the middle of the spectrum.

THE ELECTROMAGNETIC SPECTRUM

RADIO WAVES

MICROWAVES

10-3

INFRARED RADIATION

10-5

VISIBLE LIGHT

10-7

ULTRAVIOLET LIGHT

10-9

X-RAYS

10-11

10-13

GAMMA RAYS

HEAT MAKES LIGHT

To create photons, atoms need energy. Atoms are often energized by heat. For example, in older light bulbs, electricity causes the filament inside to get so hot it gives off light. Combustion, or burning, is another way photons are created.

MAKE THE GRADE

Combustion occurs when matter mixes with the gas oxygen and gives off heat and light.

FREQUENCY IS COLOR

The number of waves that move past a point in second is the frequency of the wave. In visible light, frequency is called color. Photons have a color based on the energy given off by the movement of the electrons.

MAKE THE GRADE

Light with a high frequency also has high energy. Like the colors of the rainbow, ROY G BIV can help you remember the lowest energy color, red, and the highest, violet.