How do you determine the shape of molecule?

Molecular shape is based on VSEPR Theory which states that electrons in lone pairs repel other electrons in lone pairs the most. Electrons in lone pairs repel electrons in bonding pairs less and electrons in bonding pairs repel other electrons in bonding pairs the least. To determine a molecules shape: Work out which is the central atom and how many electrons it has in its outer shell (this is the same as the group it is in) Add the number of bonds being formed Divide by two to find the total number of electron pairs Take away the number of bonds formed to work out the number of lone pairs of electrons From the number of bonding and lone pairs find the corresponding shape.