O2 Lewis Structure

O2 Lewis Structure

O2 (oxygen) has two oxygen atoms. In the lewis structure of O2, there is a double bond between the two oxygen atoms, and on each oxygen atom, there are two lone pairs.


Here’s how you can draw the O2 lewis structure step by step.

Step #1: draw sketch
Step #2: mark lone pairs
Step #3: mark charges
Step #4: minimize charges
Step #5: minimize charges again (if there are)

Let’s break down each step in detail.

#1 Draw 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 O2 has two oxygen atoms, so…

Valence electrons of two oxygen atoms = 6 × 2 = 12

So the total valence electrons = 12

  • Second, find the total electron pairs

We have a total of 12 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 = 12 ÷ 2 = 6

  • Third, determine the central atom

Here, there are only two atoms and both atoms are oxygen, so we can assume any one as the central atom.

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

  • And finally, draw the rough sketch
O2 Lewis Structure (Step 1)

#2 Mark Lone Pairs

Here, we have a total of 6 electron pairs. And one O — O bond is already marked. So we have to only mark the remaining five 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 atom is left oxygen.

So for left oxygen, there are three lone pairs, and for right oxygen, there are two lone pairs.

Mark the lone pairs on the sketch as follows:

O2 Lewis Structure (Step 2)

#3 Mark Charges

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

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

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

For right oxygen atom, formal charge = 6 – 4 – ½ (2) = +1

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

O2 Lewis Structure (Step 3)

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

#4 Minimize Charges

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

O2 Lewis Structure (Step 4)

In the above structure, you can see that the central atom (right oxygen) forms an octet. Hence, the octet rule is satisfied.

Also, the above structure is more stable than the previous structures. Therefore, this structure is the stable lewis structure of O2.

Next: CO Lewis Structure

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