Is O2 Ionic or Covalent? (And Why?)

Is O2 Ionic or Covalent

O2 is a covalent (nonpolar covalent) molecule because when one nonmetal combines with another nonmetal, it usually forms a covalent molecule (or compound). Here, both the atoms (O) are nonmetals. So when they combine, it forms a covalent molecule.

Well, now you have got to know that O2 is a covalent molecule, but let me explain the in-depth reason why O2 is a covalent molecule.

If you are a visual learner like me, then here is a short one minute video for you.

Why is O2 a Covalent molecule?

As mentioned above, you can simply remember that when the nonmetal combines with another nonmetal, the bond between them is a covalent bond.

Here in O2, both the atoms are nonmetals.

Hence the bond between them is a covalent bond.

How does the covalent bond form in O2?

In O2, there are two Oxygen atoms; 

About Oxygen (O):

Oxygen atom have 8 electrons.

The electrons arrangement in Oxygen (O) is 2, 6.

So the outermost orbit of Oxygen atom has 6 electrons.

Now in order to achieve a stable octet, the Oxygen atom needs 2 more electrons.


Hence during the chemical reaction, the Oxygen atom will gain 2 electrons from the combining atom to form a stable octet.

What happens when O and O combine?

When O and O combine with each other, both the Oxygen atoms mutually share their 2-2 electrons with each other.

Because of this, both the Oxygen atoms will have 8 electrons in their outermost orbit.


As a result, both the oxygen atoms will have a stable octet.

And finally, as the bond formed between the oxygen atoms is due to the mutual sharing of electrons, it is considered a covalent bond.

Thus, O2 is a covalent molecule.

Is O2 polar covalent or nonpolar covalent?

In order to know whether O2 is a polar covalent molecule or nonpolar covalent molecule, we have to check the electronegativity difference of the combining atoms.

If the electronegativity difference (ΔEN) is less than 0.4, then the bond is nonpolar covalent bond. 

If the electronegativity difference (ΔEN) is between 0.4 to 1.7, then the bond is polar covalent bond. [1] [2] [3] [4] [5]

Now the electronegativity of Oxygen = 3.44.

So for O2, the electronegativity difference (ΔEN) = 3.44 – 3.44 = 0

This value is less than 0.4, which indicates that the bond between both the Oxygen (O) atoms is nonpolar covalent bond.


Hence, O2 is a nonpolar covalent molecule.

I hope you have understood the reason why O2 is a nonpolar covalent compound.

Check out other compounds to see whether they are ionic or covalent;
Is H2S Ionic or Covalent?
Is NaBr Ionic or Covalent?
Is Na2O Ionic or Covalent?
Is CO Ionic or Covalent?
Is HF (Hydrogen fluoride) Ionic or Covalent? 


Jay is an educator and has helped more than 100,000 students in their studies by providing simple and easy explanations on different science-related topics. With a desire to make learning accessible for everyone, he founded Knords Learning, an online learning platform that provides students with easily understandable explanations.

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