This week we had a lot going on in class. We did many different activities to help us better our understanding of the VSEPR theory and how molecular and electron domain geometries work.

            For the first half of this week, we worked online building our models that we had already learned about from our balloon and gum drop lab. We created a molecular orbital to represent our molecule and we could use this orbital to find out a lot of information. We looked at the dipole moments that occurred in the molecule and the individual dipole bonds that were present. From this we could see the partial charges in atom and could even better understand the partial charges in the molecule by looking at the electrostatic potential map. Atoms in the molecule that were the most electronegative appeared red on the map and the atoms that were least electronegative appeared as a cool color, either blue or green. We could also see the bond angles that were present in the geometries even though we already knew this from the worksheets and lectures that we had done previously.

            We found out from this lab that the unpaired electrons on the central atom are electron clouds that push down on the bonds of the molecule and reduce their angles and this is why they sometimes deviate away from their standard value.

            We also talked a little bit about pi and sigma bonds this week. Pi bonds occur when there is an overlap of the p orbitals while sigma bonds occur when there is an overlap of the s orbitals or sp orbitals. This concept was a little complex at first to understand but made more sense to me when I understood that sigma bonds occur in all bonds while pi bonds occur in bond orders that are higher than one (i.e.: a double or triple bond). For a double bond there is one pi bond and one sigma bond while for a triple bond there are two pi bonds and one sigma bond.

          The last thing we talked about this week is hybridization. This has to do with the amount of bonds and unshared pairs of electrons around the central atom in a lewis structure. For example if there are 2 bonds the hybridization is sp, if there are 3 it is sp2, and so on. Eventually you need to start using the d orbital. To reflect on this topic I thought it was quite easy and simple to understand, all you have to do is be able to count.

          To reflect on the entire week I thought I had a very good understanding and I participated well. At first I didnt really understand much of what was going on with bonding. This weekend I really spent an extremely long time working on chemistry and doing the quizzes online and now I feel extremely comfortable with the material. I now feel like I am a 9 on a scale of understanding the material. I am very happy because I was extremely anxious last week that I would not do well on this test, but now I am very comfortable with the stuff we've learned.

Here is a twenty minute video further explaining VSEPR theory: http://www.youtube.com/watch?v=nxebQZUVvTg