What Makes a Ship Float?
What Makes a Ship Float? A small steel ball dropped into water sinks immediately. A ship weighs thousands of tons, yet it floats on the ocean’s surface. A ship...
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How Do Removable Stickers Stick?
How Do Removable Stickers Stick? Stickers use a substance called an adhesive—a kind of glue or paste that makes them stick to a surface. Adhesives can be made from...
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How Does a Magnifying Glass Work?
How Does a Magnifying Glass Work? A magnifying glass makes the words and letters on a page look much larger because of the way in which it bend the rays of light that...
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What Causes Rain?
What Causes Rain? You know that rain falls from clouds. Water is constantly evaporated from the earth’s surface by the warmth of the sun. The invisible water...
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What Is a Sand Dollar?
What Is a Sand Dollar? Have you ever taken a walk along the beach to collect seashells and found a gray disk shaped like a silver dollar? If so, chances are you found...
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How Is Coal Formed?
How Is Coal Formed? Coal comes from plants that have been buried in the earth so long, they turned hard and black. Millions of years ago, much of the earth was swampy...
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What Is a Hologram?
A hologram is a physical structure that diffracts light into an image. The term ‘hologram’ can refer to both the encoded material and the resulting image. A holographic...
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What Are Deer Antlers Made Of?
Deer are the only animals with antlers. Antlers are solid bone growing from the foreheads of male deer and both male and female reindeer. The male deer...
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Why Do We Have Time Zones?
Why Do We Have Time Zones? Time is not same everywhere. When it is noon in New York, for example, it is still 9 a.m. in San Francisco. The sun seems to move across the...
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Where Did the Expression Charley Horse Come From?
Where Did the Expression Charley Horse Come From? If you have ever exercised too much and developed a painful muscle strain in a leg or arm, then you are acquainted...
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