Why do lone pairs impact the shape of a molecule?

• A. Lone pairs increase the number of atoms in a molecule, which changes its geometry.
• B. Lone pairs always attract bonding pairs, resulting in a linear geometry regardless of the number of lone pairs.
• C. Lone pairs do not affect molecular shape because they are not involved in bonding.
• D. Lone pairs occupy space and exert repulsive forces on bonding pairs, causing bond angles to adjust and altering the molecular geometry.

Answer: (D)

Verified step by step guidance

1. Understand that molecular shape is determined by the arrangement of electron groups (bonding and lone pairs) around the central atom according to the VSEPR (Valence Shell Electron Pair Repulsion) theory.
2. Recognize that lone pairs are non-bonding electron pairs localized on the central atom, and they occupy space just like bonding pairs do.
3. Know that lone pairs exert greater repulsive forces on bonding pairs because their electron density is concentrated closer to the central atom, which pushes bonding pairs closer together.
4. Realize that this repulsion causes bond angles between atoms to adjust, often decreasing the angles compared to an ideal geometry with only bonding pairs.
5. Conclude that because lone pairs influence the spatial arrangement of bonding pairs, they directly impact the overall molecular shape or geometry.