For teachers, the Bohr model has been a godsend. Its regular, clockwork-like structure keeps kids occupied quietly for sixty minutes. Teachers can generate highly focused questions. Students can work out right-or-wrong answers.
But after the test, what good is it?
Honestly, teachers: can students look at a Bohr model of the sodium atom, and predict its soft, shiny, metallic appearance, its chemical activity with water, and its basic behaviour? No.
Be honest, now. Can students look at a Bohr model of the chlorine atom, and predict its non-metal appearance, its binary molecular structure, its reactivity, and its acidity? No.
The only thing the Bohr model is good for is memorization, and after-the-fact rationalization. Two things that kids hate in direct proportion to their ability to care.
Well.. the Bohr atom is only a representation. A picture. So.. like all good scientists, we modify the representation, and compare it to nature. (Yes. We have to consider our students as Nature.) In our case, we test the model to see if students who use it can make better predictions and explanations that those who don't use it.
In a later post, we'll see how the Bohr model is modified to become the Ross model.
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