Dry ice is frozen carbon dioxide. It is colder than ice made from water. When it evaporates, it turns from a solid to a gas. It never turns into a liquid.
My dad helped me do some interesting experiments with dry ice. We couldn’t find the video camera, so we used my dad’s iPod Touch instead.
Dry Ice Evaporates Quickly
When we first wanted to do some experiments, we bought dry ice and put it in the freezer. But it evaporated over night. We couldn’t do anything.
Dry Ice Makes Noise
When you put metal against dry ice, it makes a noise. First I did a penny. It got very cold and squealed. Next I did a quarter. It made a louder noise. And it vibrated when I let go of it. Tongs also made the noise.
This happens because dry ice turns into a gas when it evaporates. That process is called sublimation. The metal is warmer than the dry ice, so putting it on the dry ice causes the dry ice to sublimate. Carbon dioxide gas pushes against the metal and causes sound waves. The dry ice is pressed against the metal, and there are places where gas gets trapped between the ice and the metal. When some of the gas gets released through a small opening, it makes a noise. And that noise then vibrates the metal.
Dry Ice Can Blow Up a Balloon
Then I put two small pieces of dry ice in a balloon, and tied it. The dry ice started to sublimate and release carbon dioxide. And that made the balloon get bigger. I didn’t put enough dry ice in the balloon to blow it up all the way or pop it. Next time, I’ll use more.
Dry Ice Puts Out a Candle
For my next experiment, I put a lit candle in a glass bowl. Then I put dry ice in the bowl with it. The flame went out in a couple of seconds. Then, I tried to relight it. But when the matches we in the bowl, they went out.
This happened because the carbon dioxide pushed all of the oxygen out of the bowl, and fire needs oxygen.
Dry Ice Makes Fog
We took the candle out of the bowl and put in some warm water in it. It looked like smoke. But instead of going up, it moved up the sides of the bowl, then down the sides of the bowl to the counter. When I blew into it, it poofed out.
Dry Ice Blows Up a Zip Lock Bag
For the last experiment, we put warm water and dry ice in a Zip-Lock bag. It was supposed to get big and pop open. But it just developed leaks instead.
Sir Isaac Newton is a famous mathematician and physicist who lived from 1642 to 1727. Newton described how “normal” liquids or fluids behave. A newtonian fluid changes its viscosity only when it freezes or when it turns to a gas. Newtonian fluids also take the same shape as their containers.
Non-Newtonian fluids don’t behave this way. They are strange substances that are a solid when under pressure and a liquid when not under pressure.
I made mine with cornstarch, water, and blue food coloring. Ketchup, blood, yogurt, gravy, pie fillings, and mud are other examples.
You can mix your own by combining 1/8 cup water with 5 tablespoons of cornstarch. Then just mix and play with it with your hands. Try squishing it into a ball. Then let it go.
Even my sister thought it was cool.
I wanted to see metal rust. This experiment didn’t cause rust, but it did make metal change color. Mom says we can do an rust experiment later.
I mixed 1/4 cup white, distilled vinegar and a pinch of salt in a small jar.
I pulled about 20 pennies out of my bank and put them in the jar.
My book said to us iron nails but all we had was steel. So I scrubbed the steel nails with a scouring pad and put them in too.
My book said that it would take about 15 minutes. But we waited several days.
The copper from the pennies and the vinegar combined to form copper acetate. The copper in the copper acetate covered the nail with copper.
I like the show Avatar: The Last Air Bender. I wish I bend fire and water and earth and air, like they do. Today I learned how to bend light, which is almost as cool.
Light normally travels in straight lines. When light goes through water, it bends. This is called refraction.
Here is what I did to bend light:
Step. 1: Put a coin into an empty bowl.
Step 3. Have someone slowly pour water into the bowl. Make sure you don’t let the water move the coin.
As if by magic, you’ll see the coin appear. The coin seems to appear again because the light changed direction in the water!
In real life, you can be a light bender.
For my birthday, I got a Smithsonian crystal-growing kit. I learned that crystals are formed when atoms attach themselves together in patterns.
First, I grew the yellow one, called “golden citrine.”
I mixed the golden powder with boiling water, and stirred it.
Once everything was dissolved, I let it cool for 5 minutes.
I put a rock in the cup, so that the crystals could grow on something.
I then poured the liquid into the cup, and put a few crystals of the chemical on the rock.
Then I had to wait. (I think I’m good at waiting.) By morning, crystals had started growing.
After a week, it looks like this:
Out of the cup, it looks like this:
I am just a kid, and I am already a scientist! Today I learned about color.
My hypothesis is that you can get different colors by mixing them.
Let me tell you what I did. I mixed color tablets with water, and then held the test tubes up to the window.
First I did blue and yellow one at a time. Then I held them together. Guess what blue and yellow make when mixed? Green!
Here are some other combinations I tried:
Blue plus red makes purple.
Yellow plus red makes orange.
Try this experiment yourself.