Today’s Fun with Frederick and Fleming is one that you shouldn’t do at home, as it involves liquid Nitrogen which is about 320 degrees below zero in its liquid state. It must be handled with care, as it can cause severe burns.
The first experiment that we did involved soaking a graham cracker in liquid nitrogen. After dripping the excess off, we would take a bite. As long as we chewed quickly, it didn’t burn our tongues. What happened was the extreme cold resulted in the warm humid breath that we all have, to condense, which is why the fog ended up forming.
The second experiment with the balloon shows just how much air can expand and contract. As the air is cooled, it quickly contracts and with the liquid nitrogen, it actually gets cold enough that some of the oxygen will liquefy. You can see the contraction by seeing how the balloon looks like it is almost empty. Then as it warms back up, the air expands again, and the balloon is back to its original size.
The final experiment we did today was with roses and liquid nitrogen. When almost anything is brought to an extreme cold temperature, it becomes very brittle. You have probably felt a rose petal before and it was pretty soft. Now the rose petal is so brittle that it breaks into many tiny pieces. When those pieces warm up again, they are soft as before.