Ozone (O3) is an allotrope of oxygen and contains three oxygen atoms. In the lewis structure of ozone, there are one double bond and one single bond. Also, there are charges in two oxygen atoms in O3 lewis structure. Lewis structure of O3 can be drawn by starting from valence electrons of oxygen atoms in several steps. Each step of drawing the lewis structure of O3 is explained in detail in this tutorial. After drawing the lewis structure of NH3, you can decide shape of the O3 molecule.
In the lewis structure of NH3, you can see there are one double bond and one single bond between oxygen atoms. From three oxygen atoms one oxygen atom has one lone pair. Another one has two lone pairs and remaining one has three lone pairs. Also, one oxygen atom has a -1 charge and another oxygen atom has a +1 charge.
There are several steps to draw the lewis structure of O3. When you follow these steps properly, you can learn how to draw a lewis structure quickly and properly.
Important: Drawing the correct lewis structure is important to draw resonance structures correctly.
There is only oxygen as an element in ozone. Oxygen belongs to the group VIA and contains six electrons in its last shell. Now we know how many electrons includes in valence shells of oxygen atom.
To find out total valence electrons given by a particular element, you should multiply number of electrons of the valance shell by the number of atoms of that element.
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, O3, Total pairs of electrons are 9.
Because there is only oxygen as an element, no need to worry about selecting the center atom. Therefore we can draw the sketch of O3
After determining the center atom and sketch of O3 molecule, we can start to mark lone pairs on atoms. Remember that, there are total of nine electron pairs.
If there are charges on atoms in the above structure, they should be marked as the next step. Yes, there are charges on two oxygen atoms as the below figure. Determining the charges is important to find the best lewis structure. That's why we are trying to find charges.
Also, we can see one oxygen has only six electrons in its last shell. Therefore, this structure is not stable and impossible. in the next step, we will correct it.
Because one oxygen has only six electrons, we convert a lone pair on center oxygen atom to make a bond with that oxygen atom as in the following figure.
Now, you can see, every oxygen atom has eight electrons in their valence shells. Therefore, this structure is much stable than previous structure. But, we cannot convert more lone pair to bonds. So, this structure is the best lewis structure of O3.
A oxygen atom has six electron in its valence shell. In O3 molecule, there are three oxygen atoms. Therefore, there are total of 18 valence electrons in ozone molecule.