physical-chemical change

A Cool Experiment

This experiment is one that you can try the next time you take a bath. Have you ever noticed that you feel cold after a hot bath? Actually, there is more than one reason that you could feel chilled when you get out of the tub. If the water was very warm, then the air will feel cooler by comparison, but even if the water was cool and the air was warm, you could still feel a chill.

A Model of the Water Cycle

The Water Cycle is one of the major topics students are expected to understand in science. This is because water is such an important resource for food production, industry, and daily life. To help understand how the water cycle works, lets make a working model, using some common, household items.

Polymers and Slime

Polymers are fascinating molecules that are made up of long chains of smaller molecules. You can imagine them as long strings of beads or strands of spaghetti. For this activity, we will use a process called cross-linking to tangle up the polymers in white glue to change its properties, and make some "slime" for us to play with.

A Watched Pot

This experiment came from researching an experiment on cooked vegetables. As I was boiling each vegetable sample, I had quite a bit of time to watch the water boil. If you have ever watched a pot of water boil, did you notice all the strange things the bubbles did? No? Then it is time to go back to the stove and boil some water.

States of Matter

I collect books of science experiments, and it amazes me how many still teach the three states of matter. I thought that this time, we would look at the FOUR states of matter. (Actually, there are more states of matter, but these four are the common ones.)

Ice and Soda

This week's experiment came to me from my good friend Bob Cox. He told me about the trick and wanted to know why it worked. It took some thought and testing to come up with a theory of what is happening and then several e-mails to experts to confirm that I was on the right track.