Is BeBr2 Polar or Nonpolar? (And Why?)

BeBr2 is a NONPOLAR molecule.

But why? 

And how can you say that BeBr2 is a nonpolar molecule?

Want to know the reason?
Let’s dive into it!

BeBr2 is a NONPOLAR molecule because both the bonds (Be-Br bonds) are identical and BeBr2 has symmetrical geometry which cancels out the bond polarity.

Let me explain this in detail with the help of BeBr2 lewis structure and its 3D geometry.

Why is BeBr2 a Nonpolar molecule? (Explained in 3 Steps)

BeBr2 is a nonpolar molecule because it does not have any pole of positive charge and negative charge on it.

Let me explain this to you in 3 steps!

Step #1: Draw the lewis structure

Here is a skeleton of BeBr2 lewis structure and it contains two Be-Br bonds.

(Note: If you want to know the steps of drawing the BeBr2 lewis dot structure, then visit this article: BeBr2 lewis structure, Or you can also watch this short 2 minute video).

So from the above diagram we have come to know that the BeBr2 molecule has two Be-Br bonds.

Now in the next step we have to check whether these two Be-Br bonds are polar or nonpolar.

Step #2: Check whether individual bonds are polar or nonpolar

The chemical bonds can be either nonpolar, polar or ionic depending on the difference of the electronegativity values (ΔEN) between the two atoms.

Have a look at the above image.

• 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. 
• If the electronegativity difference (ΔEN) is greater than 1.7, then the bond is an ionic bond. ^{[1] [2] [3] [4]}

Now let’s come to the example of BeBr2 molecule. It has two Be-Br bonds.

You can see the electronegativity values of Beryllium (Be) and Bromine (Br) atoms from the periodic table given below.

From the above image;

• Electronegativity of Beryllium (Be) = 1.57 ^[5]
• Electronegativity of Bromine (Br) = 2.96 ^[6]

Now let’s see the polarity of each bond.

For Be-Br bond;
The electronegativity difference (ΔEN) = 2.96 – 1.57 = 1.39
This value lies between 0.4 to 1.7, which indicates that the bond between Beryllium (Be) and Bromine (Br) is polar.
Hence, each Be-Br bond is a polar covalent bond.

You can see in the above image that because of electronegativity difference, the partial positive charge (ẟ+) appears on the Beryllium atom (Be) and partial negative charge (ẟ-) appears on the Bromine atoms (Br).

But wait, this alone won’t tell you whether the entire BeBr2 molecule is polar or nonpolar.

So let’s proceed to the next step to check the symmetry of the BeBr2 molecule.

Step #3: Check whether the molecule is symmetric or not

Have a look at this 3D structure of BeBr2. You can see that the structure of BeBr2 is symmetrical. 

The beryllium atom is at the center and it is surrounded by 2 bromine atoms which are equidistant as well as at equal angles.

As both the bonds (Be-Br) are symmetrical and the BeBr2 molecule has a symmetrical geometry, their bond polarity gets canceled with each other.

Because of this, there are no positive and negative poles of charges on the overall molecule of BeBr2.

Hence, the BeBr2 molecule is a nonpolar molecule.

I hope you have understood the reason behind the nonpolar nature of BeBr2 molecule.

See the polarity of other molecules to make your concepts clear:
Is AsCl3 Polar or Nonpolar?
Is N2H2 Polar or Nonpolar?
Is SbF5 Polar or Nonpolar?
Is HOCl Polar or Nonpolar?
Is SiH3Br Polar or Nonpolar?