Chemistry 11 Block 2-1 (Conrad, Shanny, Minh, Steve)

When atoms are bonding, they ofter bond with some angles. A simple theory that enables the chemist to correctly predict the geometries of most substances is the valence-shell-electron-pair-repulsion-theory. We can say that as VSEPR.

Basicly VSEPR will have three situtions.

1, Three atoms. Example BeCl2

Cl----Be----Cl      In this example, we calculate the angle between two non central atoms with the central atom.  Therefore the angle betwee Cl and Cl is 180. We call it LINEAR shape.

2, Four atoms. Example BF3

                     F     F
                      \    /
                        B
                        /
                       F                             The angle between F and F is 360/3=120
We call it Trigonal planar.

3, Five atoms. Explam CH4

                         H
                        /
                 H--C--H
                      /
                    H                                This one is special. When five atoms are bonding with a central atom. The angle will be 109.5