1. The Shapes of Molecules  Most molecules are 3-Dimensional molecules.  Molecules are found to have certain shapes.  Example;  a pyramid, linear, planar shape, etc.  It all depends on valence electrons around the atoms and how they repel each other.

2. The Shapes of Molecules  The theory used to predict and explain shapes of molecules is called VSEPR (or Valence Shell Electron Pair Repulsion Theory.)  Electron repulsion in the molecules atoms is the basis of molecules having different shapes. Hence the theory above…

3. Example 1; Water  Water has a bent shape (or V-shape)  This is because the 2 lone pair electrons (non-bonding electrons) repel the bonding pairs. Hence, the e’s take up positions as far apart as possible from one another.

4. Example 2; Ammonia  Ammonia has a trigonal pyramidal shape.  Can you see why it has a ‘pyramid’ shape??? Trace it with a pencil.  This is because the lone pair electrons (non-bonding electrons) repel the bonding pairs. Hence, the e’s take up positions as far apart as possible from one another.

5. Example 3; Carbon tetrachloride  a.k.a tetrachloromethane

6. Task  Paste the Table 6.2 (given handout) in your exercise book, after these notes. Use a whole page.  Do the Revision Questions from the Text, Page 116, Numbers 6, 7, 8.  Read pages 118 and 119 and answer Revision Question 11, Page 120.