Thoughts by Richard Bleil
Chemists have a different sense of humor. Take, for example, the chemistry show that I was asked to give. It wasn’t really one show, but rather a weeklong series of events for different groups at a science museum in Pierre, SD. I think they were sorry they asked me.
A weeklong series of shows? Are you kidding me? I used to love demonstrations, but being an educator, it’s more than just “oh, look, colors”. No, there was always an explanation that went along with it. So, I grabbed a few students, packed a bunch of chemicals in my vehicle (that I probably should not have been hauling without a proper chemical transport license), and off we go.
The museum billed it as “extreme chemistry”, so, challenge accepted. I performed things like the thermite explosion, and curiously a couple of metal explosions. Pretty much everybody knows that sodium explodes in water, but it turns out that the entire family of metals with sodium (the “alkali metals”) react violently. So, I packed lithium, sodium and potassium. The Girl Scout troop show was the day before the big finale, so I thought they might enjoy helping out. I explained that I had a remote-control car that would explode, and I needed help deciding what to pack in it. So, we got some water, and I threw a piece of lithium in it. Not as violent as the other metals, it just fizzed and smoked, which in an of itself is a cool thing to see a metal do. Then I threw in sodium metal, which fizzed…and boom! Fiery explosion. Then I threw in potassium, and BOOM! Immediate explosion. “So which metal should I use?” I asked, confident that they would say potassium. But, no, they chose Sodium. They said the delay would be more dramatic. And they were right.
So inside of the remote-control car, I packed three pieces of sodium, one in each hump over the front tires, and one in the “cockpit”. I led the audience outside, at dusk, where I had set up a kid wading pool, with a plastic shield facing the audience so there is no splash, and a ramp up to the water. I set the car on the ramp and drove it up. “Plunk.” Into the water it fell. And…nothing. Behind me I heard a boy say, “but nothing happened.” At that moment, BOOM! The first sodium chunk went off, blowing about two-thirds of the plastic car body out of the pool, over the guard, to land burning on the concrete. My assistants started saying we needed a fire extinguisher, but I just smiled knowing that being on the concrete, there would be no danger of damage. BOOM! The second piece went off, and finally BOOM! The third. The girl scouts were correct; it was definitely dramatic.
But my favorite demonstration was the rose. See, there’s a lovely little compound (that is all too easy to make) that is stable in water, but a shock-sensitive explosive when dry. A pile of it is more powerful than the explosive used in hand grenades, but usually, chemists will just schmear a thin layer of the liquid and let it dry, making a little “pop” that is more startling than dangerous. Me? No, not enough.
I bought two roses and loaded the head of one of the roses with this chemical. Before the show, I would pour a little more of the liquid into it and let it dry. Inside the building, later that night, the show commenced. Throughout the demonstrations, I would pick up the safe rose, and say something like, “I love roses, they’re so pretty”, and put it down for another demonstration. “I love roses,” I would later say smelling the safe one, “they smell so good” only to put it down, and more demonstrations. Finally, I said “I love roses”, picking up the loaded one, “sometimes, they explode.” I tapped it on the edge of the table, and BOOM! The rose exploded.
But that’s not the end of the story. See, it was not completely dry, and unbeknownst to me, it sprayed the still wet chemical in a fine invisible mist onto the carpet in front of the table. Now, when I taught, I would always pace, walking back and forth, and my demonstrations were no different. For the rest of the show, every time I walked in front of the table, there would be little “pops” from the still drying chemical. It became like a running joke for the rest of the show, and I really played on it. This accidental demonstration pretty much made the show.