NO (Nitric Oxide) Lewis Structure and Resonance Structures | VSEPR Rule

NO (Nitric oxide) is an oxide of nitrogen. It's lewis structure can be drawn by following VSEPR rule. Number of electrons in the valence shells are used to draw the stable lewis structure and it is used find the resonance structures of NO.

NO | Nitric Oxide

Nitric oxide is a simple molecule which contains only two atoms; oxygen and nitrogen. Due to its simple structure (NO has only two atoms), we can easily draw the lewis structure of NO by following VSEPR rule.

Lewis structure of NO

Most stable lewis structure of NO is shown below. There is a double bond between nitrogen and oxygen atom. Also, there is an unpaired electron on nitrogen atom.

Steps of VSEPR rule to draw lewis structure of NO

Following VSEPR rule steps are followed to draw the lewis structure of NO and they are explained in detail in next sections. If you are a beginner to lewis structure drawing, follow these sections slowly and properly to understand. Because NO is a simple molecule, you can catch basic fundamental theories of lewis structure drawing.

1. Find total number of electrons of the valance shells of nitrogen atom and oxygen atom
2. Total electrons pairs
3. Center atom selection
4. Put lone pairs on atoms
5. Check the stability and minimize charges on atoms by converting lone pairs to bonds until most stable structure is obtained.

Drawing the correct lewis structure is important to draw resonance structures correctly

Total number of electrons of the valance shells of H₂SO₄

Nitrogen belongs to the group VA elements series. Therefore, it has five electrons in its valence shell. Oxygen has six electrons in its last shell because oxygen is located at group VIA.

• Total valence electrons given by nitrogen atom = 5

• Total valence electrons given by oxygen atoms = 6 *1 = 6

There are no charges in H₂SO₄ molecule.

• Total valence electrons = 6 + 5 = 11

Total valence electrons pairs

Total valance electrons pairs = σ bonds + π bonds + lone pairs at valence shells

Total electron pairs are determined by dividing the number total valence electrons by two. For, NO molecule, Total pairs of electrons are 5. Therefore, one electron exist as an unpair electron.

Center atom and sketch of H₂SO₄ molecule

There are no difficulties to select center atom because there is only two atoms in the molecule. Therefore, sketch can be drawn as below.

Mark lone pairs on atoms

• There is only one bond between nitrogen and oxygen atom. Therefore, there are four more valence electrons pairs and a unpair electron to mark on oxygen and nitrogen atoms.
• First, start to mark remaining four valence electrons pairs as lone pairs on outside atoms (on oxygen atoms). Three valence electrons pairs can be marked on oxygen atom. Then, there are one valence electrons pair and unpair electron to mark on nitrogen atom.
• Next, mark one valence electrons pair and unpair electron on nitrogen atom.

Charges on atoms

Charges on atoms is important to find the most stable lewis structure. Therefore, we should try to find charges on atoms if there are.

After, marking electron pairs on atoms, we should mark charges of each atom. Oxygen atoms will get a -1 charge and Nitrogen atom get a +1 charge. However, overall charge of molecule is zero.

Check the stability and minimize charges on atoms by converting lone pairs to bonds

When charges exist on lot of atoms in an ion or molecule, that structure is not stable. We should try to reduce charges on atoms as much as possible. Now, we are going to reduce charges on drawn structure if it is possible.

One lone pair in oxygen atom is converted to a bond. Then there is a double bond between oxygen and nitrogen atom.

Now, there are no charges in oxygen atom and nitrogen atom. Therefore this structure should be the stable lewis structure of nitric oxide (NO).

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