On a chilly day, there's an easy way to make your cold hands feel warmer. Rub them together---fast! Why does rubbing your hands make them warmer? You are made up of molecules, just like all other...
Hot and Cold
Hot and Cold Hot and Cold
How does a gasoline engine work?
When a gasoline engine runs, matter is changed from one form to another, and Liquid gasoline flows through a pipe from the tank to the engine. On the way, it passes through a special part that...
Matter forever!
After a log burns in a fireplace, only a few handfuls of soft ashes are left. Most of the matter in the log seems to be gone. But is it really gone? No! It has simply changed into other kinds of...
Making changes
You can change matter from one form to another by making molecules speed up and slow down. This project will show you how. A melting race Make sure the glasses are at room temperature. Put an ice...
Slowing down molecules
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...