Experiences with liquid nitrogen

I won't explain how to do the experiences but I'll describe them. This is for safety reasons. I don't wan't any mail in my postbox written: "I'm freezed. What will I do?"

If you want to mke them, go ahead. I'm not responsible.

Th liquid nitrogen has one particular caracteristic: It's VERY, REALLY VERY COLD. That's why it's is studied in Criogeny, branch of Physics that speaks about VERY low temperatures.

Experience #1:

In the first experience we will show a flower petal reaction with liquid nitrogen. When we dive the poor live poetal in ti nitrogen and take it out, the petal will apear as a thin glass. You can BREAK it. If wait some seconds with th ex-petal in your hand, the petal will come back to its original state: smooth. But dead.

Experience #2:

In this experience we will see the contraction of the air (and of the rubber two). Here you put a full baloon in the nitrogen. It will contract. And the rubber will look like plastic. When you put it out -TADA- the baloon will come back to its normal form: air and rubber.

Experience #3:

Here we will see also a contraction but in high scale. At first we need a lead bell. A lead is a very maleable material. It's so maleable that if you try to play the bell it won't sound a single note. When you dive it in the liquid nitrogen -TADA- it will ring!

Experience #4:

If you dive a ruber tube in the nitrogen it will become hard and you can BREAK it.