VSEPR

Valence Shell Electron Pair Repulsion Theory!
VSEPR is the theory used to predict molecular shapes.  Because each region of electron density (lone pair, single bond, double bond, triple bond) is negatively charged, the regions of electron density repel one another as much as possible.  This repulsion dictates the shape of the molecule or polyatomic ion.  If you're having trouble visualizing these 3-dimensional shapes, try the PhET simulation we looked at in class:
http://phet.colorado.edu/en/simulation/molecule-shapes

Have a good weekend and don't forget to look at the OWL assignments that are currently posted.

Lewis Structures

As with everything, your ability to understand and draw Lewis Structures depends upon 3 equally important things.  #1 - Practice drawing Lewis Structures.  #2 - Practice drawing Lewis Structures some more.  #3 - Most importantly, everyone needs to practice drawing Lewis Structures.  We'll work through some more examples in class and (hopefully) do some practicing in class, but you really really really really need to practice them yourself.  I've posted the lab info for the experiment we're doing after break, take a peek for some more practice using Lewis Structures.

On Friday, VSEPR.  What's VSEPR?  Come to class on Friday...

Lab exam

A few people have asked about the lab exam you will have this week, specifically how to study/prepare for it.  To give everyone the same info, here's the reply I sent to someone who asked:
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Hopefully you're already prepared. ;)  I might review some of the techniques and procedures we've consistently used throughout the semester; things like error handling, graphing, different types of glassware, etc.  Because this is more of a techniques and procedures exam, it's not necessarily something that can be studied for.  As I've said, the exam is not going to be a bunch of experiment-specific detail (What was room temperature for the Al + HCl experiment?, What color was the nickel solution in the Clandestine Lab experiment?, etc).
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Let me know if you have any further questions, I'm not sure how much more detail I can go into about the lab exam, but you can always ask.

Electron configurations, etc

We've been looking at electron configurations and what we can do/predict with them.  Sizes, charges, stability, magnetism.  Don't forget about the OWL assignments that are posted.

All the nitty gritty of the electron world...

Monday and today we've been exploring the world of the electron a bit more.  The vast majority of chemistry is really a study of the electron: where are they, why are they there, where do they move, when do they move, how fast do they move.  On Monday, we looked at quantum numbers as a way to address electrons, but writing out explicit quantum numbers can be a bit ponderous, so today we looked at a shorthand way to express quantum numbers with electron configurations.  Electron configurations describe the energy levels and orbitals that are occupied (or might be occupied) in an atom or ion and provide a very useful tool for studying electrons.  Practice them.

Light!!

We've been looking at the nature of light for the last 2 days (as well as getting exams back and going through problems) and have just gotten to the point of using that light to explore the structure of atoms. Next week, the fun will be beyond measure.  On Monday, I promise there will be fire.

Have a great weekend.  Volleyball has their final home games of the year tonight and tomorrow, and football has their last home game tomorrow.