CHEM 101A Lecture Notes - Lecture 5: Viscous Liquid, Vsepr Theory, Weak Interaction

• School: University of Arizona
• Department: Chemistry
• Course: CHEM 101A
• Professor: Laura Van Dorn

Document Summary

Lewis structures can be used to determine shape around an atom in a molecule. To determine shape, figure out how many groups are around the central atom in the structure. Then use valence shell electron pair repulsion (vsepr) theory to determine shape. The most stable arrangements keeps these groups as far away as possible. An atom surrounded by two groups is linear (bond angle of 180 degrees) An atom surrounded by three groups in trigonal (bond angle of 120 degrees) An atom surrounded by four groups is tetrahedral (bond angle of 109. 5 degrees) Use number of groups around an atom to determine geometry. Ignore multiple bonds just count atoms and lone pairs. Any atom surrounded by only two groups is linear and has a bond of angle of 180 degrees. Any atom surrounded by three groups is trigonal planar with a bond angle of 120 degrees. Solid line used for bonds in a plane.