Eggs-tra Bounce: What Did You Eggs-pect? - Experiement #346

"Can an egg be changed chemically by placing it in different compounds?

You will need:
2 whole raw eggs (in shell)
glass of water
glass of vinegar

What to do: Put one egg in a glass of water and let it stand for a full 24 hours. Place the other egg in the vinegar and let it stand for the same length of time.

What happens: The egg in the water remains the same, while the egg in the vinegar compound now feels and looks like a rubber ball, and no longer has a shell! If you drop it a short distance into the sink, it will actually bounce! Now you know how this experiment got its name.

Why: In the vinegar, a chemical change took place in the eggs. The acetic acid (vinegar) reacted with the calcium carbonate of the eggshell. The change cause the shell to soften and disappear, while the egg in the glass of water did not chemically change. Chemists would say that the shell of the egg in the vinegar becomes "decalcified"."

What happened when CKS tried it?: As soon as we put the eggs in the bowls, the egg in the vinegar had bubbles STRAIGHT away!

The next day, the shell was gone and it looked sort of yellowish and it was squishy and bigger than the egg from the water.

I tried bouncing it in the sink. I bounced it 4 times and then on the 5th time, it popped and the yolk came out. All that was left was a skin and the yolk.

The other egg was hard and small and really white with the shell still on - it didn't seem any different to me.

CKS rating: 5 stars - Better than TV!

Dry Goods - Experiment #331

"Molecules of air can even stop paper from getting wet in a glass of water.

You will need:
small glass
napkin or paper towel
glass bowl
water

What to do: Crumple the paper and place it in the bottom of the glass. Make certain it is tight so that the paper will not fall out. Fill the bowl with water. Now, turn the glass upside down over the bowl and lower it until it touches the bottom of the bowl. Lift the glass straight up out of the bowl. Continue to keep it upside down as you dry around and inside the rim of it. Now, take the paper out of the glass.

What happens: The paper inside the glass remains dry.

Why: When the glass is pushed into the water, the molecules of air do not escape but instead are pressed together and act as a shield between the water and the paper. Some water enters the glass, but not enough to wet the paper. The molecules of air take up enough space to block it."

What happened when CKS tried it?: The water spilled out of the bowl onto the table because it was too full. I had to clean it up and empty some water out of the bowl. Then when I tried again, the paper was dry and I didn't spill. Make sure you don't fill it up too high!

CKS rating: 5 stars - Better than TV!

Color Fun - Experiment #25

"Is green really green?

You will need:
strip of paper towel
green felt-tipped pen or 1 drop of green food coloring
jar or glass with 1 inch of water

What to do: Make a spot of color about 2 inches from one end of the strip of paper towel. Hang the strip in the jar so the spot is above the water and the end of the strip is in the water. Let it stand for 15 to 20 minutes.

What happens: The green spot is gone but above the original spot, the paper has turned blue, and above that the paper is yellow.

Why: Most dyes and inks are combinations of coloring substances which can be taken apart by adding water or alcohol. Water moves up the paper the same way as sap rises in trees. As the water moves up, it dissolves the green spot and gradually moves the color up the strip of paper. But since the colors that make up green - blue and yellow - do not move at the same rate, they separate."


What happened when CKS tried it? I tried ink and food coloring. The food coloring was opposite from the ink because the blue is at the top, the green is in the middle, and only a little yellow at the bottom. And on the ink, there is a lot of yellow on the top and there is a little green in the middle, and some blue on the bottom. Ink worked better. Advice from CKS for when you try this at home: don't forget to label your paper towel strips.

CKS rating: 5 stars - Wow, better than TV!