What is the molecular geometry of NF_3?

• A. Tetrahedral
• B. Trigonal planar
• C. Bent
• D. Trigonal pyramidal

Answer: (D)

Verified step by step guidance

1. Determine the Lewis structure of NF_3 by counting the total valence electrons: Nitrogen has 5 valence electrons, and each Fluorine has 7, so total electrons = 5 + 3 \times 7 = 26 electrons.
2. Draw the skeletal structure with Nitrogen as the central atom bonded to three Fluorine atoms, then distribute the remaining electrons to satisfy the octet rule for each atom.
3. Identify the number of bonding pairs and lone pairs around the central Nitrogen atom. Nitrogen forms three single bonds with Fluorine atoms and has one lone pair of electrons.
4. Use the VSEPR (Valence Shell Electron Pair Repulsion) theory to predict the molecular geometry. Four regions of electron density (3 bonding pairs + 1 lone pair) around Nitrogen correspond to a tetrahedral electron geometry.
5. Since one of the four regions is a lone pair, the molecular geometry is trigonal pyramidal, not tetrahedral, trigonal planar, or bent.