Shape and Electronic Geometry

When drawing the Lewis Structure of different elements and compounds, the structure has a shape and a geometry. The shape of the structure is determined by the number of bonds and direction of them about the central element as well as the number of lone pairs. The electronic geometry is determined the number of electronic domains around the central element.

Combining the two: http://intro.chem.okstate.edu/1314f00/lecture/chapter10/vsepr.html

Shape explanation: This site gives some background on the different shapes of the structures. http://www.smc.edu/projects/28/Chemistry_10_Experiments/Ch10_Molecular_Shapes.pdf

Here is an example of water, its shape is bent:

Electronic geometry explanation: https://ch301.cm.utexas.edu/help/ch301/geometries.pdf

Here is an example of H2O, its geometry is tetrahedral (this is because of the four different regions shown in the bottom left picture):

Lewis Structures

Lewis structures was the first things that we talked about, and this helped us learn everything after it. A lewis structure is a method of drawing compounds and showing their valence electrons, where bonds are shown with lines and lone pairs are shown with dots.

Here is a quick explanation on how to draw them: http://www.chem.ucla.edu/harding/lewisdots.html


Here are a couple compounds that you can practice drawing lewis structures for:

Here is a link to a video where they show you how to draw them. This can be helpful when you are drawing the ones from above: https://www.khanacademy.org/science/chemistry/chemical-bonds/copy-of-dot-structures/v/drawing-dot-structures

Here is a link to a website that provides any lewis structure you need so you can check your answers: http://www.wolframalpha.com/widgets/view.jsp?id=689aa5a01c216d8b16ed0250cebdc702

Here is an example of  the Lewis Structure for water.

Electronegativity

Electronegativity is just one of the things that we have talked about throughout this unit that goes along with chemical bonding. This number is placed on the periodic table and will tell you which elements have higher electronegativity than others. This number dictates the bonds they will make or whether or not the elements are non polar, polar, or ionic bonds. 

When you look at the periodic table, the electronegativity values tend to increase as you go to the right and up. This pattern will help when you are asked to put several bonds in order from most to least ionic without using the values themselves.

Here is a link that helps explain electronegativity: http://www.chemteam.info/Bonding/Electroneg-Bond-Polarity.html