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.


2 comments:

  1. Interesting observation. Both of my General Chemistry books seem to follow this logical approach, though lewis e-dot formulas are covered in an earlier chapter. Also the symmetry aspect is fairly basic, though it seems about right for intro level Gen-chem.

    I've got the 5th addition of Ebbing's "general chemistry" and "Chemistry the science of change" from Brown, LeMay and Bursten. Though I've never really looked at these texts from a "teaching" perspective, so I may be off the mark with what you consider adequate...

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