Question

which molecular geometry is illustrated above? image shows a molecular structure (likely nh₃) with n and h atoms, and options: bent, tetrahedral, trigonal pyramidal, trigonal planar

Explanation:

The molecule shown is $\ce{NH3}$ (ammonia). The central nitrogen atom has 3 bonding pairs (with H atoms) and 1 lone pair of electrons. The electron - pair geometry is tetrahedral, but the molecular geometry (considering only the atoms) is trigonal pyramidal because the lone pair repels the bonding pairs, causing the three H atoms to form a pyramid - like shape around the N atom. Bent geometry is for molecules like $\ce{H2O}$ (2 bonding pairs, 2 lone pairs), tetrahedral is the electron - pair geometry here (not molecular), and trigonal planar is for molecules with 3 bonding pairs and no lone pairs (e.g., $\ce{BF3}$).

Answer:

trigonal pyramidal