I know Halloween's past now, but I can't resist posting this video. Teacher Chris Bergmann of Kinard Core Knowledge Middle School in Fort Collins, Colorado, demonstrates pumpkin 'carving' using explosive gases.
I bet those kids will remember that science class forever!
Peter
Need more teachers like that! I was lucky enough to have a teacher similar to that back in high school. (I do remember her name, but I won't post it here). First day of class, she took this paint can, with a small hole in the top and near the base. She hooked up the hose to the lower hole, and filled it with the gas from the burners on the table, then unhooked the hose, and lit the gas at the top.
ReplyDeleteFor a while, it had a nice, steady flame. She remarked it might make a nice light for camping or something, and we ignored it while she lectured. Then, all of a sudden, *BOOM*! Once the air/gas mixture was just right inside the can was just right, all the remaining gas exploded. Was enough force to blow the lid off and leave a dent in the ceiling.
I mentioned this to some people at our 30-year reunion. Everyone remembered it in vivid detail! :)
I had a chemistry professor my freshman year at Cornell U. who aimed for a different explosion* during each lecture; if I remembered his name, I'm sure he wouldn't mind me sharing it. :)
ReplyDelete* They weren't all actual explosions, per se, but they were at least interesting chemical reactions -- or chemistry-related songs, in some cases.
On the first day, he poured 1 ml of hexane into a watch glass and set it on fire. It burned, calmly. He then took the same amount of the same fuel, poured it into a 1-liter plastic bottle, capped it, shook it, uncapped it, and had an elderly assistant apply a lit wick to the open bottle from a meter away... BOOM! (Aerosol ftw!)
In later lectures, he increased the quantity to 2 ml and then 3 ml; the latter shook chalk dust from the board! Then there was thermite, which melted out the bottom of a steel crucible (into a waiting ceramic one); ammonium triiodide, and compound so sensitive that it takes the touch of a piece of paper to make it undergo a rapid chemical decomposition that sounds like an explosion; hydrogen and oxygen mixed in soap bubbles and chased down by an enterprising student with a lit wick on a meterstick, in increasingly stoichiometric mixtures. :)
It also became something of a game to see who was asleep or otherwise not paying attention near the end of class, when he initiated such explosions... :D
I had one like that in high school too! He was a PHD Physicist on sabbatical from TI! That was the most fun class I ever had!!!
ReplyDeleteI was in the last class at my Jr. High to see the effect of Na + H2O. The reason being the teacher dropped the wrong piece of sodium into the fishtank of water. He managed to get around the desk and reach the back of the classroom before the herd of us 9th graders did! Scratch one fish tank.
ReplyDeleteLittleRed1