In stormy weather, raindrops trickle down the outside of the window. But sometimes, in very cool weather, the inside of the window is cloudy and wet. Where does the film of water on the inside of the...
Speeding up molecules
Can you fry ice cubes? You can try---but if you heat ice cubes in a pan, they won't be ice cubes any more. The ice will melt into water. And, after a while, the water will boil and turn into steam....
Hard, wet, and invisible
Which is strongest---a stone wall, running water, or blowing wind? A stone wall can stop the wind. But running water can wear down a stone wall. And moving air in the wind can dry up water. So, each...
Building blocks
Atoms are the \"building blocks" of matter. They fit together to make all the things there are. Most kinds of matter are made of atoms that are joined together. These groups of joined atoms are...
Kinds of matter
How many kinds of matter are there? So many that if you started to count them, you probably would never finish! But if you could sort out the atoms in all of that matter, you would find that there...
Bits and pieces
> What's in a sand castle? Millions and millions of tiny grains of sand. The many grains of sand are packed together to make a single shape---a castle with towers, walls, and bridges. And what...
What’s the Matter?
What's the matter, do you ask? I'll tell you right away. It's everything around you, as you work, or sleep, or play. A chair is matter, a table, too, and so is a rock or tree. A cloud, a star, a...
“Something” for everyone
What's in the package? You won't know for sure until you open it---but it's fun to guess. You can tell about how big the present inside the wrapping paper is. And you can tell about how heavy it...
What’s the Matter?
What’s the Matter? What’s the Matter?
Putting machines to work
Turn the key at the back of the alarm clock once . . . twice . . . three times. At first the key turns easily. But as you keep winding, the key turns harder and harder. Finally the clock is wound as...
