Sally M. Walker

Rocks can be made of many different minerals. By looking at rocks closely, we can tell where they were formed and what conditions they were created in....

You know that magnets hold pictures on a refrigerator. But have you ever found a magnet's north pole? Or turned an ordinary paper clip into a magnet? Now you can....

The sun, lightbulbs, and flickering fires all bring light to our world. But have you ever watched light rays move? Or saw how light rays reflect off objects? Now you can....

What do a doorstop, a butter knife, and the front of a boat have in common? All of them are wedges! Wedges are simple machines....

What do jar tops and water-bottle lids have in common? Both of them are screws! Screws are simple machines....

What do flagpoles and some window blinds have in common? They use pulleys to perform work! Pulleys are simple machines....

What do hammers, wheelbarrows, and brooms have in common? All of them are levers! Levers are simple machines....

What do staircases, dump truck beds, and ramps have in common? All of them are inclined planes! Inclined planes are simple machines....

Soil can be found almost everywhere on Earth. Sand is a soft soil that is found in deserts. Loam is soil that is great for growing plants. But how are these types of soils different? And how are they made? Explore the amazing world of soil in this book....

People, animals, machines, and wind all make sounds. But have you ever seen how sound waves move? Or made a sound wave bounce? Now you can! Explore sound with the fun experiments you'll find in this audiobook....

Minerals are fascinating resources that have a variety of uses. A diamond is a mineral that is sought after for its beauty. Salt is a mineral that adds flavor. But do you know what minerals are made of, or how to identify a mineral? Explore the amazing world of minerals in this book....