Water has some amazing properties. It is the only natural substance found in all three states -- solid, liquid and gas -- within the range of natural Earth temperatures. Its solid form is less ...

To compare the density of two substances like clay and water, you can compare the weight of the same “size” or volume, of each substance. As you show the animation, explain that since a piece of clay ...

Study reveals contaminants in some bottled water. Oct. 16, 2008 — -- It's a front-page story all across the country — but you have to read between the headlines. The Environmental Working ...