Science In A Snap

Thursday, July 5, 2012

Yes, This Really Is Science!

Tell your parents this is a very important learning tool. These are not just cookies, they are an experiment in density, volume, and states of matter!

Adult Supervision Required:

What You Need:

Ask Yourself:

You are about to use an electric beater to mix up those egg whites really, really fast. What do you think will happen to the egg whites? Will they look and feel any different when you are done whipping them?

What You Do:

Warm up the eggs to room temperature
Preheat the oven to 250 degrees F.
Cover the cookie sheets with foil, dull side up
Place the egg whites, vanilla and vinegar in a bowl
Using a mixer, whip the mixture until it is white and frothy
Beat in the sugar a little at a time until you have added it all
Keep whipping until the mixture is stiff and glossy
Lightly and gently stir in the chocolate chips
Drop the batter by spoonfuls onto the cookie sheets and bade for about one hour until cookies are lightly browned
Let them cool before removing from cookie sheets

The Big Science Words:

By making these cookies you are learning about density and volume, and also about states of matter!
Density and volume: by whipping, you have changed the egg whites from a liquid to a foam. You have also expanded them to three times their original size! This happens because egg whites are mostly protein, which traps air very well. When you whip them, those protein molecules grab onto the air and trap it, making and holding onto the bubbles. You have also changed their size, or volume. They are much bigger now because of all that air. But, the air bubbles do not make them more dense, or heavy. That's why these cookies feel so light; they are mostly air!
States of matter: by cooking the egg whites (or any eggs for that matter) you have changed the liquid egg into a solid. That's because of the cool properties of the proteins in egg. Cooking causes those protein molecules to change shape. They bunch up instead of being loose and stretched out. That makes them solid!

What You Need:

Ask Yourself:

Directions:

Fill the glass with the clear soda
Drop the raisins into the glass and watch
(If you want to continue the experiment, you can try other items in your kitchen to see which ones work best. Try things like macaroni noodles, lentils, corn, or dried cranberries and see what happens!)

The Big Science Words:

Now you've discovered that the raisins in the glass will begin to "dance" by bobbing up and down with the bubbles in the soda. This happens because of a few big science words: nucleation, density, volume, and mass.
Nucleation: this is when the air bubbles from the soda collect in all the little pockets and wrinkles in the raisin.
Density, Volume, and Mass: those little air bubbles are giving those raisins their own little "floaties." When the air bubbles attach to the raisin, they increase its volume, or make it bigger. But, because they're just bubbles, they don't increase its mass; they don't make it any heavier. So when the raisin is covered with bubbles it becomes less dense than the soda around it and it floats. When the bubbles pop at the surface, it becomes more dense than the soda again, and down it goes!

Boiling Water!

What You Need:

Ask Yourself:

Make a guess about what texture you think you will have when you are done making the play dough... will it be hard, soft, squishy, crumbly...?

What You Do:

The Big Science Words:

You have made a squishy, pliable substance
This is called a polymer
Many polymers are synthetic (that means made from man made materials) but play dough is a really cool natural polymer
A polymer is a substance that contains large molecules made up of lots of tiny molecules that are bonded together; that is what gives it its fun texture

Did You Know?

National Play dough Day happens on September 16th! Make this fun scented play dough and make the celebration official!