Normally, Kimberly Lawler-Sagarin’s place is at the head of this classroom in the Schaible Science Center, lecturing to the twenty ﬁrst-year students in her course Chemistry in the Natural World. But on this autumn afternoon she has settled into a back-row seat to watch her students troop, one by one, to the front of the class to do the lecturing.
The temporary role reversal is one of the signature features of this chemistry class for non-science majors. In addition to the usual laboratory work and written assignments, students are required to practice and present a chemistry demonstration that makes basic concepts understandable and engaging for grade-schoolers. By the end of the term, the demonstrations will be videotaped and posted on YouTube for grade-school science teachers and students to access. Some students might later take their shows on the road to offer their demonstration at area grade schools, where they are a favorite at “fun science” events.
Today is only a ﬁrst run-through for Lawler-Sagarin’s class, a kind of dress rehearsal for the big chemistry shows to come. Students are scrambling to assemble their lab equipment and props (“Does anybody have any red food dye?”) and practicing their patter (“How many of you kids have heard of Aladdin’s magic lamp?”) before they run through their demonstrations for their professor and classmates.
Once the show starts, the demonstrations prove to be as enlightening as they are entertaining. A ﬁrst-year student named Cody Rank takes his turn at the front of the class, heating small piles of various salts in lab dishes. The ﬂames that result range in color from a garish orange to a deep purple, Rank explains, depending on each element’s characteristics for absorbing and releasing energy. He goes on to explain that these variations in color are the basis for the art behind ﬁreworks displays. As the ﬂames dance, Rank’s classmates play the part of duly impressed grade-school kids, oohing and aahing at the show of colors. In the back row, Lawler-Sagarin approves, too, but also reminds Rank to keep a ﬁre extinguisher close at hand for future demonstrations.
Later, there will be more students practicing more demonstrations: how to pierce a balloon with a sharp needle without popping the balloon (a lesson in the basics of polymer chains), how vinegar and baking soda react to form enough carbon dioxide to blow up a rubber glove to gigantic proportions (an introduction to chemical reactions), how to manufacture a foaming tube of elephant-size toothpaste, complete with extra-large elephant toothbrush props (an illustration of the role of catalysts in launching reactions). “This is not your cookbook lab,” Lawler-Sagarin says. “We leave room for ﬂexibility and fun.”
Learning through trial and error is a feature of any science class with a lab component; but in this class, mastering and polishing the demonstrations to the point at which they’ll stand up to the scrutiny of sixth graders is part of the pedagogy, too. As any parent who has ever had to help a child with homework can testify, it is one thing to understand an academic concept, but quite another to understand it well enough to explain it to a kid. “Because they have to explain the concepts behind their demonstration, they end up learning the concepts in more depth,” Lawler-Sagarin says.
That’s to say nothing of the oral communication skills needed to stand in front of a video camera or a room full of elementary-school students and crisply explain thorny concepts like molecular polarity. And if the demonstration goes awry? That’s not necessarily a bad thing, says Lawler-Sagarin. “It gives us the chance to look at the concept again, to do a little problem solving,” she says. “It’s never a bad thing to understand why something didn’t work.”