If a molecule contains multiple lone pairs, how do they typically influence its shape?

When a molecule contains multiple lone pairs, they exert a significant influence on the molecular shape and bond angles. Lone pairs of electrons occupy space around the central atom and tend to repel neighboring bonding pairs more strongly than bonding pairs repel each other. This repulsion is a key factor in molecular geometry, as described by the VSEPR (Valence Shell Electron Pair Repulsion) theory.

When lone pairs are present, they push the bonded atoms closer together, leading to alterations in bond angles compared to what would be observed in a molecule with only bonding pairs. For example, in a tetrahedral arrangement without lone pairs, the bond angles are typically 109.5 degrees. However, the presence of lone pairs can reduce these angles as the lone pairs repel the bonding pairs more strongly.

This pronounced alteration of bond angles due to lone pair repulsion is a crucial element in determining the overall shape of the molecule, making the assertion that they alter bond angles significantly accurate.