Today was a bad day in everything but my teaching. We are starting “shape.” This is how I think of Lewis structure/VSEPR stuff. We are taking steps towards thinking in three dimensions, which is one of the wonderful things about chemistry.
I managed to start at the beginning. I reviewed their prior knowledge of valence electrons. I then defined Lewis structures. Then I did the LS for the elements whose valence electrons they had just found for their POD. Then I started with two simple molecules (methane and ammonia) and demonstrated “easy” ones. Then I outlined a method for figuring out the number of bonds and the number of non-bonding electrons. Throughout this I would show them 2, and then they would do one. Tomorrow we will start of with practice (I modified a worksheet from another teacher’s website). Then I will show them some examples with multiple bonds and define resonance. Then we will practice more.
Baby steps. Lots of practice. Despite it being a fairly teacher led day, the students seemed quite positive. I think I actually taught something properly, instead of jumping in all willy-nilly with only enthusiasm and assumptions.
