Teaching with tangerines

I am standing in the classroom holding a tangerine in each hand. They aren’t just any tangerines; each one has two crumpled-up balls of paper taped to it. In an attempt to make my students conceptualize atoms I am using a home-made model of two water molecules. I am not sure if the kids are focused on me holding two tangerines or if they are really pretending that the tangerines are the oxygen atoms in water. Some of them are laughing, which means at least they’re having fun.

It’s a shame that I don’t have a real model set, but tangerines and crumpled paper might do the trick. I am trying to help them understand the link between the structure (and number) of a molecule and its chemical formula. Many of the 10th, 11th, and 12th graders still don’t know how to read a chemical formula, which is, I think, a necessary step to reading and understanding chemical equations (descriptions of chemical reactions: the making and breaking of chemical bonds).

Sometimes, in order to justify me being here, I like to tell myself I am a better teacher than most Mozambican teachers. It would be kind of silly to be living here if I wasn’t. Despite my justification, I make a lot of mistakes (ones that impair my students’ ability to learn) and my Portuguese is still limited when it comes to describing chemistry. In comparison, the Mozambican chemistry teachers are speakers of Portuguese and they have practice under their belt, making many of their explanations clear, at least when it comes to the student getting the right answer. The most I can hope for is that my teaching here demonstrates another style of teaching (one more focused on understanding, visualizing, and reasoning) for the students that will one day become teachers themselves. Sometimes I doubt even my ability to do this, but then I remind myself that I haven’t yet seen a Mozambican teacher do anything like use home-made models of water molecules in class.