Dirtmeister Science Lab
Challenge Question:
How can you force a physical change in matter?
What You Do
1. Learn about matter and its different forms.
2. Read my Science Lab on matter and think about the challenge question.
3. Predict with your classmates what will happen.
4. Do the experiment. 
5. Share your results with the rest of your class. 


Dirtmeister's Science Lab
on Matter What is Matter?

Matter, matter everywhere.
There's matter in your hair.
Matter in the air.
There's even matter in a pear!
There's liquid matter, solid matter, and matter that's a gas.
Even you are matter, because you have volume and mass!

Okay, so maybe I'm not a poet, but that's how I describe the "stuff" we call matter. In trying to make sense of the universe, scientists have classified everything that exists into two broad categories: matter and energy. Simply stated, matter can be thought of as "stuff" and energy is "the stuff that moves stuff."

Matter PixNow, if you take all the "stuff" in the world, you know that there are many different types. To further simplify things, matter has been broken down into three basic types, or "states of matter": solids, liquids, and gas. (Actually there are more than three, but we're going to concentrate on the main forms here.) 

Matter can change from one state to another, which we call a "physical change." Physical changes usually occur when heat (energy) is either added or taken away. A good example of a physical change is when an ice cube melts. It starts as a solid but when you add heat, it turns into a liquid. The cool thing about a physical change is that it can be reversed. If you take the liquid water from the melted ice and cool it down again (remove the heat), it turns back into a solid! 

It turns out that heat isn't the only type of energy that can cause a physical change in matter. In my Science Lab, you'll see what happens when mechanical energy meets some wild and wacky "mystery matter"!

Here's what you'll need:
a big mixing bowl or a disposable aluminum baking dish
one 16-oz container of corn starch
a measuring cup
lots and lots of paper towels and a wet sponge for cleaning up!
  Here's what to do:
  1. Pour the dry cornstarch into the bowl.
  2. Add about 1 1/2 cups of water.
  3. Using your hands, mix the two together until it forms a thick paste. (You may have to add a little water the mixture should have the consistency of tapioca pudding!)
  4. Clear off the table around you and prepare to get a little messy!
  5. Take some of the mystery matter in your hand and let it rest in your hand. (Make sure you hold it over the bowl!)
  6. Next, grab a handful and give it a squeeze.
  7. Let a handful rest in your hand. As some falls between your fingers, try cutting it with scissors.
  8. Leave the mystery matter in the bowl and try poking it with your finger.

How can you force a physical change in matter? What happened to the state of the mystery matter when you took it out of the bowl and held it in your hand? What happened when you squeezed the mystery matter? What kind of energy was causing this change?

Before you try this Science Lab, predict what state of matter (solid, liquid or gas) your mystery matter is when it is sitting in the bowl.

When you've finished the Science Lab, share your results with the rest of your class. Based on your observations, what conclusions can you make about the state of your mystery matter? See what other tests you can come up with to prove your ideas.