Phasing out the demo

I’m struggling to make peace with phasing out class demonstrations. I am in the middle of the transition from a traditional classroom into a student-centered learning environment. This summer at ChemEd 2013 I realized that the quest for the perfect chemistry demo is outdated pedagogy that pays homage to the “Sage on the Stage” model of teaching. I wrote in my first blog post, Dr. Shakhashiri opened my eyes to the wonderful world of chemistry demonstrations. Adding class demos to my lessons literally saved my teaching career in my second year. I dedicated the first year of this blog to documenting how I implemented new class demos. Researching demos and learning new chemistry was very exciting for me as I wrote my first series of blog posts. Yet, now I feel frustrated by the class demo because my students are passively watching me “do science” for them.

Last week I spent a class period doing a series of demos as part of my chemical reactions unit. After a week in which my kids explored chemical reactions in the lab, I followed up with some “more exciting” reactions as a way of reviewing their understanding of predicting products and writing chemical equations. (I presented on this topic at ChemEd 2013 in Waterloo. My fellow chemistry teachers were excited by the lesson and my handouts are posted at ChemEd 2013 site.) The class was going along as planned, my students were sitting around a central lab table, white boards and markers in hand. After every demo I performed, they wrote out the chemical reaction to describe what they saw. The eye-opening moment for me was the big finale; I ended the day with my “thermite two ways” demo. I took the class outside to watch the famous thermite reaction. The flying sparks and the dripping molten iron created plenty of “oohhs” and “aahhhs” as students watched the awesome power of the thermite. Then, I got out my rusty cannonballs* (one wrapped in aluminum foil) and showed them “hand held” thermite.* Banging the two cannonballs together produces a loud pop and sparks. After I got a good pop and some sparks, I passed the cannonballs to a student. That’s when the magic happened. My students got so energized by watching their classmates create the hand-held thermite reaction. Each successful bang was greeted with cheers and applause. One boy was crowned the thermite master; he forced some amazing blasts out of those two cannonballs. I walked away from this day smiling at the great enthusiasm the kids had during class. But, later that day, as I started reflecting on the lesson, it hit me like a ton of bricks: it only got exciting when the chemistry was in the students’ hands. I was reminded once again that learning happens when the students engage in the process.

The flipped classroom has changed everything for me. When I moved myself from the center of the stage, my goal shifted away from teaching the perfect lesson and toward creating an engaging learning environment. I realized that kids don’t learn by watching me blow up things and light stuff on fire. Yes, I know it’s really fun for everyone, especially me, to do a big “ta-da” demo. I am the first to admit that I love demos. Yet, when I put learning as the central objective in my class, rather than performing, the outcome is unpredictable, rich and sometimes magical.

Sharon Geyer
Pomfret School, Pomfret CT

*Note: Find “Thermite reaction with rusty iron balls” at the Chem 13 News website (under May Supplemental Materials).