# How do lewis structures help predict the shape of a compund?

Lewis structure is taught in conjunction with VSEPR, Valence shell electron pair repulsion theory. To a first approximation, it doesn't matter whether the electron pairs are lone pairs or bonding pairs. They will arrange themselves in order to minimize electron-electron repulsion between electron pairs. Two electron pairs (around the central atom) will be 180$\circ$ with respect to each other; three electron pairs, 120$\circ$; four electrons pairs, and the overall structure becomes 3-dimensional, tetrahedral, and the electron pairs (bonding or not) are disposed 109.5$\circ$ with respect to each other; 5 electron pairs, trigonal bipyramidal; and 6 electron pairs, octahedral.