A simple experiment involving inversion of a conical flask over burning a candle in a dissection tray with some water can be a stimulus for open-ended, really really fun, very very challenging -- to both students and teachers alike -- problem, covering some fundamental high school chemistry.
Who says sugar is bad for children?! It's especially not bad in a chemistry classroom where it can be used to create flares and to bring chemistry alive! This is the 6th Beauties vs. Brawns challenge.
Are you a teacher and want to improve the learning outcomes of your students?
If you do, you also need to be learning, constantly, by looking for, and trying out, new ways of delivering your lessons.