Hybridization of NH3 (Ammonia) - Lewis Structure and Electron Geometry


About Ammonia

Ammonia (NH3) is sp3 hybridized, or to be more specific, the central atom of ammonia, nitrogen. We'll look at how to figure out if NH3 is hybridized in this article.

Ammonia is a colourless chemical that is utilized in fertilizer production. It's a stable hydride with one nitrogen and three hydrogen atoms in it. The chemical has a strong odour. Accepting a proton allows it to become an NH4+ ion. This section post will cover the Lewis dot structure, electron geometry, and molecular geometry of this molecule.

Lewis Structure

Lewis structures, also known as Lewis point structures, Lewis point structures, electron point structures, or Lewis electron point structures (LEDSs), contain bonds between atoms within a molecule and all lone pairs  that can be gifts. It is a diagram to show. All covalently bonded molecules and coordination compounds can be represented by the Lewis structural formula.

Gilbert N. Lewis named the Lewis structure after himself after introducing it in his 1916 article The Atom and the Molecule. Lewis structures add lines between atoms to represent shared pairs in a chemical bond, extending the concept of the electron dot diagram.

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Lewis structures use chemical symbols to represent each atom and its place in the molecule's structure. Between atoms that are linked together, lines are drawn (pairs of dots can be used instead of lines). Lone pairs of excess electrons are shown as pairs of dots next to the atoms.

Although main group elements in the second period and beyond normally react by acquiring, losing, or sharing electrons until they have a complete octet of (8) electrons in their valence shell electron configuration, hydrogen (H) can only form bonds that share two electrons.


When atomic orbitals combine to generate a new atomic orbital, this is known as hybridization. The new orbital can accommodate the same number of electrons as the old ones. The new, hybridised orbital characteristics and energy are an 'average' of the original unhybridized orbitals.

Hybridization was proposed as the best explanation for why all C - H bonds in molecules like methane are identical.

Electron Geometry

The arrangement of electron groups is called electronic geometry. When an electron that is not connected to a lone pair of electrons or another atom is found in the molecule, the shape of the molecule changes, not the shape of the electron.

The electron geometry and molecular geometry are the same if all the electron groups are bonded and there are no lone pairs.

Hybridization of NH3 (Ammonia)

To comprehend ammonia hybridization, we must investigate the surroundings surrounding Nitrogen. The atomic number of nitrogen is 7, and its ground state is 1s2, 2s2,2p3 according to its atomic number.

One 2s orbital and three 2p orbitals of nitrogen mix during the production of ammonia to generate four hybrid orbitals with equivalent energy, which is referred to as an sp3 kind of hybridization.

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Furthermore, if we look at the NH3 molecule, we can see that nitrogen's three half-filled sp3 orbitals create bonds with the three hydrogen atoms. The fourth sp3 orbital, on the other hand, is a nonbonding pair of hybridized orbitals that is generally employed to hold the lone pair together.

It is a common nitrogenous waste of aquatic creatures and an important component of terrestrial species' nutritional requirements. Furthermore, if stored in sufficient quantities, ammonia is considered corrosive as well as harmful.

FAQs on Hybridization of NH3 (Ammonia) - Lewis Structure and Electron Geometry

1. How to Calculate the Hybridization?

First, we have to write the Lewis structure to get an idea about the structure of a molecule and bonding pattern. We can use the valence concept to do so. The further step is to calculate the sigma (σ) bonds count in that molecular structure. After that, find the lone pair numbers on a given atom by using the formula,

Number of lone pairs = {(v-b-c) ∕2}

Where v = number of valence electrons in the concerned atom in a free state

c = charge on the atom

b = number of bonds formed by a concerned atom

We can calculate the steric number as,

Steric number = number of σ-bonds + number of lone pairs and then based on the steric number Assign hybridization and shape of a molecule

2. Why do Hybrid Orbitals Form Stronger Bonds?

The hybrid orbitals have identical energy. They also contain more electron density in a particular lobe compared to the other lobe. The pure atomic orbitals contain uniform charge density throughout the orbital.

The hybrid orbital overlaps the central atom with the atomic orbital of the bonded atom resulting in a stronger bond compared to the overlap of two pure atomic orbitals.

For example, an sp3 hybrid orbital has 75% of electron density in a lobe and 25% in the other lobe. The 75% electron density lobe overlap with an atomic orbital of the bonded atom results in the formation of a strong bond because of the large overlapping region.

3. What are the valence electrons in the Hybridization of NH3 (Ammonia) - Lewis Structure and Electron Geometry?

Valence electrons are the number of electrons present in an atom's outermost shell, i.e., free electrons. These valence electrons participate in bond formation by either absorbing or donating valence electrons from another atom.

The valence electrons primarily act in this way because each atom strives to establish a stable state by completing its octet.

Furthermore, because the nucleus' hold on the outermost shell is weakest because it is the furthest away, the valence electrons react to the presence of surrounding valence electrons. At Vedantu website, students can download this information in PDF format to learn anytime.

4. What is the Lewis structure of NH3?

The Lewis structure of nitrogen and hydrogen atoms reveals that a total of eight valence electrons are involved in bond formation to form a single tetra-atomic NH3 molecule.

Here, students will see how the NH3 molecule's Lewis structure is drawn:

  • To find the total amount of valence electrons, use the following formula: To make a single NH3 molecule, you'll need eight.

  • Calculate the total number of electrons required: According to the octet rule, one ammonia (NH3) molecule equals six. To become stable, one Nitrogen atom requires three electrons, while all three Hydrogen atoms require one additional electron.

  • Keep an eye out for the total number of bonds that are forming: Each oxygen and hydrogen atom has three solitary covalent bonds.

  • To find the central atom, do the following: The center atom will be nitrogen.

5. What is the Geometrical Structure of Ammonia (NH3)?

The hydrogen-nitrogen-hydrogen atoms (H-N-H) have a 107° bond angle. It is obvious that the geometrical structure of NH₃ will be distorted.

The Valence Shell Electron Pair Repulsion (VSEPR) theory states that the presence of a lone pair on the nitrogen atom causes the entire structure of NH₃ to bend, resulting in a bond angle of 107°.

The ideal bond angle for the bent geometrical diagram is 109.5°, which may surprise you.

Ammonia (NH3) has a trigonal pyramidal or deformed tetrahedral molecular shape. The reason for this is that the nitrogen atom has a single non-bonding lone pair of electrons that serves as a repulsive force on the bonding orbitals.

6. What is the electron geometry of the Hybridization of NH3 (Ammonia)?

The shape of a molecule is predicted using both bond electron pairs and lone electron pairs in electron geometry. According to the VSEPR hypothesis, electron pairs near a specific atom repel each other. Bonding electrons or non-bonding electrons can make up these electron pairs.

The spatial arrangement of all the bonds and lone pairs in a molecule is determined by electron geometry. VSEPR theory can be used to determine electron geometry.

The steps needed to make this determination are as follows.

  • Predict the molecule's core atom. It should be the atom with the largest electronegative charge.

  • The number of valence electrons in the core atom must be determined.

  • Determine how many electrons other atoms have donated.

  • Calculate the total number of electrons in the atom's core.

  • Subtract 2 from the total. This determines how many electron groups are present.

  • Subtract the steric number from the number of single bonds existing around the center atom. This tells you how many lone electron pairs are in the molecule.

  • Determine the geometry of electrons.

7. Why does hybridization happen in Ammonia NH3?

 The reasons that can justify the hybridization in ammonia molecules are- 

  1. The bond angle between the orbitals would be 90 degrees if the molecule did not contain hybrid orbits and instead had unhybridized p-orbitals participating in the bond formation. In the real world, the bond angle is nearly 107, which makes the molecule more stable by reducing the repulsion between bond pairs and between bond pairs and lone pairs.

  1. Hybridization is defined as the mixing of atomic orbitals with slightly varying energies to generate new orbitals with equal energies, as defined by the definition. This helps to keep the molecule stable. The energies of the lone pair of electrons and the bond pair of electrons in the ammonia molecule become almost equal as a result of hybridization, boosting the molecule's stability.

  1. If there is no hybridization in the ammonia molecule, the size of the orbitals having a lone pair of electrons will be different from that of the orbitals containing a bond pair of electrons. It would also be impossible to explain the geometry of the molecule, namely its trigonal pyramidal structure if hybridization did not occur.