 the number of electron pairs (both bonding and lone pairs) and use the following chart to "key out" the geometry. It is assumed that electron pairs - whether bonding or non bonding repel each other and adopt a geometrical arrangement that maximizes the distances between them. In other words the negatively charged electron groups get as far away from each other as possible because of their electrostatic repulsion. This would also be an appropriate time to point out to students the effect of a nonbonding pair of electrons on the bond angles within a molecule ( Figure 6 ). The valence shell electron pair repulsion is based on the idea that both bonding and non bonding electron pairs in the valence shell of an atom "repel" each other. Single, double and triple bonds all count as one domain. Vsepr is remarkably successful in predicting structures of molecules and ions of main group elements. Start with a one sentence answer. Set this model aside. Linear 6 0 You: How many faces this time? Two electron pair domains (terminal atoms or nonbonding electron pairs) assume a linear structure. Pairs of electrons which are shared hold atoms together in molecules and are known as "bonding pairs". Students can also use their models to determine the bond angles for each shape. Students spend time holding and manipulating their models, and are readily able to recall the information later in the course.