This year we had a conflict in dates so we did the program in the fourth grade classrooms in all 3 schools.
We told them about how cold the liquid nitrogen is: -196 oC (Celsius), -320.44 oF (Fahrenheit), or 77K (Kelvin).
Cold enough to give someone frostbite in seconds.
It is made from the most common gas found in air by cooling it with a super refrigerator.
The properties of things change when they are cooled with liquid nitrogen.
We showed them that rubber balls sound like marbles when dropped on the floor.
Flowers break into tiny shards if you bend them.
And bananas can be used to drive a nail into a board.
We didn't get pictures of all the different things we did because we were busy with the demonstrations.
I had a student turn on a glow stick but they couldn't figure out how to turn it off.
So I showed them that cooling it would slow the chemistry that makes the light and it would go out.
Then it would light again when it warmed up.
Frost formed from moisture in the air and we were able to make it "snow" in the classrooms.
I told them a story about when I was an astronaut and went to Neptune.
There I found many different kinds of creatures (they looked a lot like balloon animals).
One had 6 feet so it was a hexapod.
Another was tetra eyed (4 eyes).
An albino (no pigment) eel (a long skinny kind of fish).
And several more that could only be described as ALIENS.
There were far more than would fit in my spaceship for the trip back for my classrooms full of scientists to examine.
But I knew that things will contract when they are cooled.
So I could cool the creatures in liquid nitrogen and bring them all back
The expressions on the scientists' faces as the creatures shrank into the liquid nitrogen
When I got back to earth and let the creatures warm up they all inflated to their original size and shape because all the air that had been in them was still in them.
Then we took a mixture of milk, cream, sugar, egg whites, vanilla, and a little salt.
We added liquid nitrogen while the teacher stirred and 12 seconds later we had ice cream.
It got very positive reviews.
All these experiments and lots more can be seen on this page.
