Question

The shape of ammonia molecule according to VSEPR theory is ________.

• A. triagonal pyramidal
• B. linear
• C. tetrahedral
• D. triagonal planar

Answer 1

The correct option is A triagonal pyramidal

The molecular formula of ammonia is ${\text{NH}}_3$. A nitrogen atom has five valence electrons and it needs three electrons to attain the nearest noble gas (neon) configuration. While the hydrogen atom has one electron and it needs one more electron to attain the nearest noble gas (helium) configuration.

So, nitrogen atoms share it's three valence electrons with three hydrogen atoms. While the hydrogen atoms share one electron each with the nitrogen atoms. Thus, one lone pair of electrons remain in a nitrogen atom.

The hybridization in ammonia molecule is ${sp}^3$ hybridization and the shape is distorted tetrahedral because of the presence of lone pair of electrons because the repulsion of lone pair- bond pair is greater in comparison to bond pair-bond pair.

There are three covalent bonds formed in an ammonia molecule. Therefore, there are three bond pairs. Since there are three bond pairs and one lone pair, the shape of the molecule according to VSEPR theory will be trigonal pyramidal.