H2O (Water) is a covalent (polar covalent) compound because when one nonmetal combines with another nonmetal, it usually forms a covalent compound. Here, H is a nonmetal and O is also a nonmetal. So when they combine, it forms a covalent compound.
Well, now you have got to know that H2O is a covalent compound, but let me explain the in-depth reason why H2O is a covalent compound.
If you are a visual learner like me, then here is a short one minute video for you.
Why is H2O a Covalent compound?
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 H2O, the H atom is a nonmetal and the O atom is also a nonmetal.
Hence the bond between them is a covalent bond.
How does the covalent bond form between H and O?
In H2O, there are two atoms;
H and O.
About Hydrogen (H):
Hydrogen atom have 1 electron.
It has only 1 orbit and there is only 1 electron in this orbit.
Now in order to achieve a stable duplet, the Hydrogen atom needs 1 more electron.
Hence during the chemical reaction, the Hydrogen atom will gain 1 electron from the combining atom to form a stable duplet.
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 H and O combine?
When H and O combine with each other, the Hydrogen atoms and Oxygen atom mutually share their 1-1 electrons with each other.
Because of this the hydrogen atom will have 2 electrons in its outermost orbit and similarly the oxygen atom will also have 8 electrons in its outermost orbit.
As a result, the hydrogen atom will have a stable duplet and the oxygen atom will have a stable octet.
And finally, as the bond formed between the hydrogen and oxygen is due to the mutual sharing of electrons, it is considered a covalent bond.
Thus, H2O is a covalent compound.
Is H2O polar covalent or nonpolar covalent?
In order to know whether H2O 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 Hydrogen and Oxygen are mentioned below. (You can see the electronegativity of all the elements from this electronegativity chart).
- Electronegativity of Hydrogen (H) = 2.2
- Electronegativity of Oxygen (O) = 3.44
So for H2O, the electronegativity difference (ΔEN) = 3.44 – 2.2 = 1.24
This value lies between 0.4 to 1.7, which indicates that the bond between Hydrogen (H) and Oxygen (O) is polar covalent bond.
But the H2O molecule has 2 lone pairs which results in an asymmetric shape of the entire H2O molecule.
Because of this asymmetric shape there are positive and negative poles of charges on the overall molecule of H2O.
Hence, H2O (water) is a polar covalent molecule.
I hope you have understood the reason why H2O is a polar covalent compound.
Check out other compounds to see whether they are ionic or covalent;
Is Hydrogen chloride (HCl) Ionic or Covalent?
Is CaCl2 (Calcium chloride) Ionic or Covalent?
Is NH3 (Ammonia) Ionic or Covalent?
Is CH4 (Methane) Ionic or Covalent?
Is MgCl2 (Magnesium chloride) 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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