Temperature Of Liquid Nitrogen

Recently, I attended a demonstration presented by the Franklin Institute with my Kindergarten class. The topic was liquid nitrogen. For a group of five and six year olds, this was more of a variety show than a scientific lecture, but for me it was a mind bending exercise. The coldest thing that I can imagine is ice; 32 degrees F. When we were told that the temperature of liquid nitrogen was -320 degrees, I could not fathom something that cold! How much colder can something get than ice? I was also confused by the state of this matter. It is a liquid that appears to be boiling, which we later found out, it was. How could something that cold be boiling? I was stumped. 
The woman presenting this demonstration was very articulate and explained everything in a manner that the children could understand. She proceeded to show them what would happen if certain items were submerged in this mysterious liquid. First was the rubber ball. When she took it out of the liquid nitrogen and threw it against the wall, it shattered. Pieces of the ball went everywhere. The children laughed with delight. To them it was pure magic. To me, it just reinforced my disbelief about just how cold this substance is. I could not wrap my brain around it. The ball was only in the bubbly vat for a few seconds and it went from bouncing to breaking. Next up was the balloon. When it was submerged into the liquid, it seemingly lost all its air. She explained that the air in the balloon did not escape but turned to liquid at such an extremely cold temperature. Sure enough, there was liquid in the balloon. Liquid air? I had never heard of such a thing. Within a few seconds of being back to room temperature, the liquid disappeared and the balloon was inflated again. Again, the children were very pleased and, again, I was surprised. I have never seen matter go from one state to another this quickly before. The hour was filled with fun demonstrations and children being called up on stage to help. One student got to use a banana as a hammer once it was dipped into the liquid nitrogen.
All in all, it was a very entertaining and informative event. The children were awed by the magic of it all and I was very impressed to have learned so much about the temperature of liquid nitrogen and how it can change the state of matter instantly.