The ammonia molecule (NH_3) in the diagram has the observed bond orientation because:

• A. the nitrogen atom forms double bonds with each hydrogen, causing a linear geometry
• B. all four electron pairs around nitrogen are shared equally, resulting in a tetrahedral geometry
• C. the lone pair on nitrogen repels the bonding pairs, resulting in a trigonal pyramidal geometry
• D. the hydrogen atoms are arranged in a planar triangle to minimize repulsion

Answer: (C)

Verified step by step guidance

1. Identify the central atom in the ammonia (NH_3) molecule, which is nitrogen (N).
2. Determine the number of valence electrons around nitrogen: nitrogen has 5 valence electrons, and each hydrogen contributes 1 electron, totaling 8 electrons to be arranged.
3. Recognize that nitrogen forms three single bonds with hydrogen atoms, using 3 pairs of electrons, and has one lone pair of electrons remaining.
4. Apply the VSEPR (Valence Shell Electron Pair Repulsion) theory, which states that electron pairs (bonding and lone pairs) around a central atom repel each other and arrange themselves to minimize repulsion.
5. Understand that the lone pair on nitrogen occupies more space and repels the bonding pairs, causing the molecule to adopt a trigonal pyramidal geometry rather than a planar or tetrahedral shape.