To accurately determine the characteristics of an ammonia (NH₃) molecule, we need to consider its Lewis structure, bond polarities, molecular shape, and overall molecular polarity. Let's outline each characteristic step-by-step:
1. Bond Polarities:
- The ammonia molecule consists of nitrogen (N) and hydrogen (H) atoms.
- Nitrogen is more electronegative than hydrogen.
- When atoms with different electronegativities form a bond, the electrons are not shared equally. This inequality creates a polar bond.
- Therefore, the N-H bonds in NH₃ are polar.
2. Molecular Shape:
- To determine the shape, we start by drawing the Lewis structure of NH₃.
- Nitrogen has 5 valence electrons, and each hydrogen has 1 valence electron, summing up to a total of 8 valence electrons.
- In the Lewis structure of NH₃, nitrogen is the central atom bonded to three hydrogen atoms. This arrangement utilizes six electrons, with one lone pair of electrons remaining on nitrogen.
- The electron pairs (both bonding pairs and lone pairs) repel each other and arrange themselves as far apart as possible.
- Due to the lone pair on nitrogen, the shape is not tetrahedral but rather a trigonal pyramidal shape.
3. Molecule Polarity:
- The molecule's polarity is influenced by the shape and the polarity of the bonds.
- Despite the individual N-H bonds being polar, the shape of the molecule determines if these dipoles cancel out or if a net dipole moment exists.
- In NH₃, the lone pair on the nitrogen contributes to a net dipole moment, causing the molecule to be polar overall.
Given these analyses, we can correctly fill in the blanks:
The bond polarities are polar, the molecular shape is trigonal pyramidal, and the molecule is polar.
So, the correct answer is:
The bond polarities are polar, the molecular shape is trigonal pyramidal, and the molecule is polar.
