what shape will this molecule be? a) linear b) bent c) trigonal pyramidal d) tetrahedral

Explanation:

Step1: Analyze the molecule (NH₃)

The molecule is ammonia (NH₃). The central nitrogen atom has 5 valence electrons. It forms 3 single bonds with hydrogen atoms (using 3 electrons) and has 1 lone pair of electrons (2 electrons). So, the central atom has 3 bonding pairs and 1 lone pair.

Step2: Determine the electron - pair geometry and molecular shape

The electron - pair geometry (considering both bonding and lone pairs) around the central N atom is tetrahedral (because the number of electron groups is 4: 3 bonding groups and 1 lone pair). But the molecular shape (considering only the bonding groups) is determined by the arrangement of the atoms. When there are 3 bonding pairs and 1 lone pair in a tetrahedral electron - pair geometry, the molecular shape is trigonal pyramidal. Linear shape occurs when there are 2 bonding pairs and 0 lone pairs (e.g., CO₂). Bent shape occurs when there are 2 bonding pairs and 1 or 2 lone pairs (e.g., H₂O with 2 bonding pairs and 2 lone pairs). Tetrahedral molecular shape occurs when there are 4 bonding pairs and 0 lone pairs (e.g., CH₄).

Answer:

C) trigonal pyramidal