Thursday, March 24, 2011

Lewis structures, VSEPR theory thoughts

My fourth time through this topic in lecture and lab is yet an other new beginning. I rewrote my handout AGAIN for the third time. My supplementary handout started out as a four-page document, evolved into an eight-page document and has now become a 12-page document. Whewwwww! Challenging. Every time I teach this topic I realize more and more exactly what the students don't understand. The strange thing is that out of the three textbooks I own on chemistry, only one actually explains it thoroughly from the lewis dot models to the VSEPR shapes to the dipole moments/polarity and overall symmetry of each molecule. Is this a new topic? I doubt it. I'm trying to understand why none of the book authors can sufficiently explain it.