Cl2 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 (Cl) are nonmetals. So when they combine, it forms a covalent molecule.
Well, now you have got to know that Cl2 is a covalent molecule, but let me explain the in-depth reason why Cl2 is a covalent molecule.
If you are a visual learner like me, then here is a short one minute video for you.
Why is Cl2 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 Cl2, both the atoms are nonmetals.
Hence the bond between them is a covalent bond.
How does the covalent bond form in Cl2?
In Cl2, there are two Chlorine atoms;
About Chlorine (Cl):
Chlorine atom have 17 electrons.
The electrons arrangement in Chlorine (Cl) is 2, 8, 7.
So the outermost orbit of Chlorine atom has 7 electrons.
Now in order to achieve a stable octet, the Chlorine atom needs 1 more electron.
Hence during the chemical reaction, the Chlorine atom will gain 1 electron from the combining atom to form a stable octet.
What happens when Cl and Cl combine?
When Cl and Cl combine with each other, both the Chlorine atoms mutually share their 1-1 electrons with each other.
Because of this, both the Chlorine atoms will have 8 electrons in their outermost orbit.
As a result, both the chlorine atoms will have a stable octet.
And finally, as the bond formed between the chlorine atoms is due to the mutual sharing of electrons, it is considered a covalent bond.
Thus, Cl2 is a covalent molecule.
Is Cl2 polar covalent or nonpolar covalent?
In order to know whether Cl2 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 Chlorine = 3.16.
So for Cl2, the electronegativity difference (ΔEN) = 3.16 – 3.16 = 0
This value is less than 0.4, which indicates that the bond between both the Chlorine (Cl) atoms is nonpolar covalent bond.
Hence, Cl2 is a nonpolar covalent molecule.
I hope you have understood the reason why Cl2 is a nonpolar covalent compound.
Check out other compounds to see whether they are ionic or covalent;
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Is CaSO4 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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