O3 Lewis Structure in 6 Steps (With Images)

So you have seen the above image by now, right?

Let me explain the above image in short.

O3 lewis structure has three Oxygen atoms (O). There is 1 double bond and 1 single bond between the Oxygen atoms (O). There is 1 lone pair on the central Oxygen atom, 2 lone pairs on double bonded Oxygen atom and 3 lone pairs on single bonded Oxygen atom.

If you haven’t understood anything from the above image of O3 (ozone) lewis structure, then just stick with me and you will get the detailed step by step explanation on drawing a lewis structure of O3.

So let’s move to the steps of drawing the lewis structure of O3.

Steps of drawing O3 lewis structure

Step 1: Find the total valence electrons in O3 molecule

In order to find the total valence electrons in O3 (ozone) molecule, first of all you should know the valence electrons present in a single oxygen atom.
(Valence electrons are the electrons that are present in the outermost orbit of any atom.)

Here, I’ll tell you how you can easily find the valence electrons of oxygen using a periodic table.

Total valence electrons in O3 molecule

→ Valence electrons given by oxygen atom:

Oxygen is group 16 element on the periodic table. ^[1] Hence the valence electrons present in oxygen is 6.

You can see the 6 valence electrons present in the oxygen atom as shown in the above image.

Hence, 

Total valence electrons in O3 molecule = 6(3) = 18.

Step 2: Select the central atom

For selecting the center atom, you have to remember that the atom which is less electronegative remains at the center.

Now here the given molecule is O3 (ozone). All the three atoms are same, so you can select any of the atoms as a center atom.

Step 3: Connect each atoms by putting an electron pair between them

Now in the O3 molecule, you have to put the electron pairs between all three oxygen atoms (O).

This indicates that all three oxygen (O) atoms are chemically bonded with each other in an O3 molecule.

Step 4: Make the outer atoms stable. Place the remaining valence electrons pair on the central atom.

Now in this step, you have to check the stability of the outer atoms.

Here in the sketch of O3 molecule, you can see that the outer atoms are oxygen atoms only.

These outer oxygen atoms are forming an octet and hence they are stable.

Also, in step 1 we have calculated the total number of valence electrons present in the O3 molecule.

The O3 molecule has a total 18 valence electrons and out of these, only 16 valence electrons are used in the above sketch.

So the number of electrons which are left = 18 – 16 = 2.

You have to put these 2 electrons on the central oxygen atom in the above sketch of O3 molecule.

Now let’s proceed to the next step.

Step 5: Check the octet on the central atom. If it does not have octet, then shift the lone pair to form a double bond or triple bond.

In this step, you have to check whether the central oxygen atom (O) is stable or not.

In order to check the stability of the central oxygen (O) atom, we have to check whether it is forming an octet or not.

Unfortunately, the central oxygen atom is not forming an octet here. This oxygen has only 6 electrons and it is unstable.

Now to make this oxygen atom stable, you have to shift the electron pair from the outer oxygen atom so that the central oxygen atom can have 8 electrons (i.e octet).

After shifting this electron pair, the central oxygen atom will get 2 more electrons and thus its total electrons will become 8.

You can see from the above picture that the central oxygen atom is forming an octet as it has 8 electrons.

Now let’s proceed to the final step to check whether the lewis structure of O3 is stable or not.

Step 6: Check the stability of lewis structure

Now you have come to the final step in which you have to check the stability of lewis structure of O3.

The stability of lewis structure can be checked by using a concept of formal charge.

In short, now you have to find the formal charge on all the oxygen (O) atoms present in the O3 molecule.

For calculating the formal charge, you have to use the following formula;

Formal charge = Valence electrons – (Bonding electrons)/2 – Nonbonding electrons

You can see the number of bonding electrons and nonbonding electrons for each atom of O3 molecule in the image given below.

For central Oxygen (O) atom:
Valence electrons = 6 (because oxygen is in group 16)
Bonding electrons = 6
Nonbonding electrons = 2

For double bonded Oxygen (O) atom:
Valence electrons = 6 (because oxygen is in group 16)
Bonding electrons = 4
Nonbonding electrons = 4

For single bonded Oxygen (O) atom:
Valence electrons = 6 (because oxygen is in group 16)
Bonding electrons = 2
Nonbonding electrons = 6

Formal charge	=	Valence electrons	–	(Bonding electrons)/2	–	Nonbonding electrons
O (central)	=	6	–	6/2	–	2	=	+1
O (single bonded)	=	6	–	4/2	–	4	=	0
O (double bonded)	=	6	–	2/2	–	6	=	-1

From the above calculations of formal charge, you can see that the central oxygen (O) atom has +1 charge and the double bonded oxygen atom has -1 charge.

To minimize these charges, if you will further try to shift the electron pair, then there will be 8 + 2 = 10 electrons on the central oxygen atom.

But oxygen atom do not have the capacity to hold 10 electrons. Hence the above lewis structure of O3 is stable.

In the above lewis dot structure of O3, you can also represent each bonding electron pair (:) as a single bond (|). By doing so, you will get the following lewis structure of O3.

I hope you have completely understood all the above steps.

For more practice and better understanding, you can try other lewis structures listed below.

Try (or at least See) these lewis structures for better understanding:

CH2O lewis structure	SO3 lewis structure
C2H4 lewis structure	SF4 lewis structure
H2S lewis structure	OF2 lewis structure