School science, to be meaningful, interesting and accessible to students has to be primarily experimental. However for large classes, it is hard to provide both the space and the equipment needed to teach in this manner. This problem is particularly acute for chemistry, where the risk of mishaps with chemicals makes it difficult even to arrange demonstrations in the classroom.
I think I speak for all chemistry teachers when I say that there are certain reactions I have only read about. Chlorine is a greenish-yellow gas – I learnt this in class 8, but did not see it till the time I was teaching students in class 12, though I had spent many of the intervening years studying chemistry. In school, there was no chance to see the preparation of chlorine, though we learnt the equation and drew the diagram of the apparatus. Afterwards, it was ‘school’ chemistry and college laboratory exercises were far more advanced. I suspect this is the experience of most chemistry students – the basic descriptions and reactions – Sodium is a soft white metal, buzzes around in water, Chlorine turns Litmus red then bleaches it, … are all reactions read in the textbook and never seen. As teachers, what can we do to make sure that we give our students the experiences that are vital to their learning?
The author works with Centre for Learning, Bangalore. She can be reached at [email protected].