INTRODUCTION

CHAPTER ONE:THE SCIENTIST AT WORK

1．What Is Science?

2．Observation

3．Instruments

4．Questions

5．Experimenting

6．Finding Answers

7．Stating a Problem

8．An Hypothesis

9．The Answer

10．Summing Up

CHAPTER TWO:EXPERIMENTING WITH ELECTRICITY

1．What Is Electricity?

2．Using Electricity

3．The Dry Cell

4．Sockets and Wires

5．Lighting a Bulb

6．A Complete Circuit and a Switch

7．Conductors and Nonconductors

8．A Short Circuit

9．A Fuse

10．Heat and Electricity

11．The Electric-Light Bulb

12．Wiring the Circuits

13．Batteries and Ways to Obtain Electricity

14．Adding Volts

15．Electricity in Review

CHAPTER THREE:USING MACHINES

1．AMachine

2．The Lever

3．Kinds of Levers

4．A Lever for Experimenting

5．Pulleys

6．Wheel and Axle

7．The Inclined Plane

8．The Screw

9．The Wedge

10．The Power Shovel

11．Elevators

CHAPTER FOUR:WORKING WITH CHEMICALS

1．Molecules and Atoms ＆ Elements and Com-pounds

2．Matter and Change

3．Describing Chemical Changes

4．"Breaking"a Compound ＆ Making a Com-pound

5．Some Important Chemical Changes

6．Chemicals Every Day

CHAPTER FIVE:INTO SPACE WITH SATELLITES

1．Launching Satellites

2．Rocket Power

3．Satellite Rockets

4．Satellites—Up and Down

5．Satellite Instruments

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