3. this is a diagram of ammonia. this molecule has a central nitrogen atom singly bonded to three hydrogen…

3. this is a diagram of ammonia. this molecule has a central nitrogen atom singly bonded to three hydrogen atoms. the nitrogen atom also has one lone pair of electrons. the shape of this molecule can be classified as _______. a) linear b) trigonal planar c) tetrahedral d) trigonal pyramidal

3. this is a diagram of ammonia. this molecule has a central nitrogen atom singly bonded to three hydrogen atoms. the nitrogen atom also has one lone pair of electrons. the shape of this molecule can be classified as _______. a) linear b) trigonal planar c) tetrahedral d) trigonal pyramidal

Answer

Brief Explanations:

To determine the molecular shape of ammonia ((NH_3)):

  1. First, identify the electron - domain geometry. The central nitrogen atom has 3 bonding domains (from the three (N - H) bonds) and 1 non - bonding domain (the lone pair of electrons). The total number of electron domains is (3 + 1=4), so the electron - domain geometry is tetrahedral.
  2. Then, consider the molecular shape. The molecular shape is determined by the arrangement of the bonding domains. Since there is one lone pair and three bonding pairs, the repulsion between the lone pair and the bonding pairs causes the three hydrogen atoms to form a pyramid - like structure around the nitrogen atom.
    • A linear shape (option A) has a bond angle of (180^{\circ}) and is seen in molecules like (CO_2) with two bonding domains and no lone pairs.
    • A trigonal planar shape (option B) has a bond angle of (120^{\circ}) and is seen in molecules like (BF_3) with three bonding domains and no lone pairs.
    • A tetrahedral shape (option C) is the electron - domain geometry when there are four bonding domains (e.g., (CH_4)), but in (NH_3) there is a lone pair, so the molecular shape is not tetrahedral.
    • The shape of (NH_3) is trigonal pyramidal (option D) because of the presence of one lone pair and three bonding pairs around the central nitrogen atom.

Answer:

D) trigonal pyramidal