O3 Lewis structure

O₃ (ozone) has three oxygen atoms.

In the O₃ Lewis structure, there is one double bond and one single bond around the oxygen atom, with two other oxygen atoms attached to it. The oxygen atom with a double bond has two lone pairs, the oxygen atom with a single bond has three lone pairs, and the center oxygen atom has one lone pair.

Also, there is a positive (+1) charge on the center oxygen atom, and a negative (-1) charge on the oxygen atom with a single bond.

Alternative method: Lewis structure of O₃

Rough sketch

• First, determine the total number of valence electrons

In the periodic table, oxygen lies in group 16. Hence, oxygen has six valence electrons.

Since O₃ has three oxygen atoms, so…

Valence electrons of three oxygen atoms = 6 × 3 = 18

So the total valence electrons = 18

Learn how to find: Oxygen valence electrons

• Second, find the total electron pairs

We have a total of 18 valence electrons. And when we divide this value by two, we get the value of total electron pairs.

Total electron pairs = total valence electrons ÷ 2

So the total electron pairs = 18 ÷ 2 = 9

• Third, determine the central atom

Here, there are three atoms and all atoms are oxygen, so we can assume any one as the central atom.

Let’s assume that the central atom is center oxygen.

• And finally, draw the rough sketch

Lone pair

Here, we have a total of 9 electron pairs. And two O — O bonds are already marked. So we have to only mark the remaining seven electron pairs as lone pairs on the sketch.

Also remember that oxygen is a period 2 element, so it can not keep more than 8 electrons in its last shell.

Always start to mark the lone pairs from outside atoms. Here, the outside atoms are left oxygen and right oxygen.

So for left oxygen and right oxygen, there are three lone pairs, and for center oxygen, there is one lone pair.

Mark the lone pairs on the sketch as follows:

Formal charge

Use the following formula to calculate the formal charges on atoms:

Formal charge = valence electrons – nonbonding electrons – ½ bonding electrons

For left oxygen and right oxygen atom, formal charge = 6 – 6 – ½ (2) = -1

For center oxygen atom, formal charge = 6 – 2 – ½ (4) = +2

Here, all oxygen atoms have charges, so mark them on the sketch as follows:

The above structure is not a stable Lewis structure because all oxygen atoms have charges. Therefore, reduce the charges (as below) by converting lone pairs to bonds.

Convert a lone pair of the left oxygen atom to make a new O — O bond with the center oxygen atom as follows:

Final structure

The final structure of O₃ comprises a central oxygen atom connected to two terminal oxygen atoms through one single bond and one double bond. In this arrangement, the central oxygen atom satisfies the octet rule by forming three bonds and retaining one lone pair. The double-bonded terminal oxygen fulfills its octet by keeping two lone pairs, while the single-bonded terminal oxygen maintains three lone pairs to complete its own. This setup is the most stable because it results in a formal charge of +1 on the central atom and -1 on the single-bonded terminal atom, representing the most energetically favorable state for the molecule. Consequently, this specific electronic distribution serves as the definitive and most accurate Lewis representation of ozone.

Next: C₂H₂ Lewis structure

External video

• O3 Lewis Structure – How to Draw the Dot Structure for O3 – YouTube • Wayne Breslyn

External links

• https://whatsinsight.org/o3-lewis-structure-step-by-step-drawing/
• https://geometryofmolecules.com/o3-lewis-structure-polarity-hybridization-shape-molecular-geometry/
• https://techiescientist.com/o3-lewis-structure/
• https://www.chemistryscl.com/general/ozone-lewis-structure/
• https://topblogtenz.com/o3-lewis-structure-molecular-geometry-bond-angle-shape/
• https://lambdageeks.com/o3-lewis-structure/