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Earth and Its Neighbors 2

Before You Read 2

Earth and Its Neighbors 6

Section 1:Astronomers Make Discoveries 8

Section 2:Astronomers Discovered the Solar System 14

genre Using a Web Site Facts About Earth 18

After You Read 28

Glossary 30

Our Solar System 32

Before You Read 32

Our Solar System 36

Section 1:The Sun 37

Section 2:The Inner Planets 38

Section 3:The Outer Planets 41

Section 4:Earth in Space 44

genre Using a Web Site Other Planets Have Seasons Too 50

Section 5:Why Planets Orbit the Sun 52

After You Read 58

Glossary 60

Exploring Our Solar System 62

Before You Read 62

Exploring Our Solar System 64

Section 1:Looking at Earth 65

Section 2:The Solar System Orbits the Sun 70

Section 3:The Inner Planets 72

Section 4:The Outer Planets 78

genre Using a Web Site The Hale-Bopp Comet 84

After You Read 88

Glossary 90

Making Matter Change 92

Before You Read 92

Making Matter Change 96

Section 1:Physical and Chemical Changes 98

Section 2:Bringing Matter Together 100

Section 3:Taking Matter Apart 106

genre Reading an Encyclopedia Entry Solar Still 110

Section 4:Comparing Changes 114

After You Read 118

Glossary 120

Changing Matter 122

Before You Read 122

Changing Matter 126

Section 1:Chemical Changes 127

Section 2:Physical Changes 130

Section 3:Reversing Changes in Matter 134

genre Reading an Encyclopedia Entry Centrifuge 138

Section 4:Making Matter Change 142

After You Read 148

Glossary 150

Compounds and Mixtures 152

Before You Read 152

Compounds and Mixtures 154

Section 1:Matter Can Change Chemically 155

Section 2:Matter Can Change Physically 166

genre Reading an Encyclopedia Entry Oil Spill 174

After You Read 178

Glossary 180