Lewis Structure of Br2 (With 6 Simple Steps to Draw!) (2024)

Lewis structure of Br2 (Bromine) contains a single bond between both the Bromine (Br) atoms. And both the Bromine atoms have three lone pairs on it.

Let’s draw and understand this lewis dot structure step by step.

(Note: Take a pen and paper with you and try to draw this lewis structure along with me. I am sure you will definitely learn how to draw lewis structure of Br2).

6 Steps to Draw the Lewis Structure of Br2

Step #1: Calculate the total number of valence electrons

Here, the given molecule is Br2 (Bromine). In order to draw the lewis structure of Br2, first of all you have to find the total number of valence electrons present in the Br2 molecule.
(Valence electrons are the number of electrons present in the outermost shell of an atom).

So, let’s calculate this first.

Calculation of valence electrons in Br2

• For Bromine:

Bromine is a group 17 element on the periodic table. ^[1]

Hence, the valence electrons present in bromine is 7 (see below image).

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Hence, total number of Valence electrons in Br2 molecule = 7(2) = 14

Step #2: Select the center atom

While selecting the atom, you have to put the least electronegative atom at the center.

But here in the Br2 molecule, both the atoms are same. So you can consider any of the atoms as a center atom.

So, let’s assume that the bromine which is on the right side is the central atom.

Step #3: Put two electrons between the atoms to represent a chemical bond

Now in the above sketch of Br2 molecule, put the two electrons (i.e electron pair) between both the bromine atoms to represent a chemical bond between them.

These pair of electrons present between the Bromine (Br) atoms form a chemical bond, which bonds both the bromine atoms with each other in a Br2 molecule.

Step #4: Complete the octet (or duplet) on outside atom. If the valence electrons are left, then put the valence electrons pair on the central atom

Don’t worry, I’ll explain!

In the Lewis structure of Br2, we have just assumed the right side bromine atom as a central atom and so the left side bromine atom is an outer atom.

So now, we have to complete the octet on this left side bromine atom.

Now, you can see in the above image that the outer bromine atom forms an octet.

Also, only 8 valence electrons of Br2 molecule are used in the above structure.

But there are total 14 valence electrons in Br2 molecule (as calculated in step #1).

So the number of electrons left to be kept on the central atom = 14 – 8 = 6.

So let’s keep these six electrons (i.e 3 electron pairs) on the central atom (i.e right side bromine atom).

Now, let’s move to the next step.

Step #5: Check whether the central atom has octet or not

In this step, we have to check whether the central atom (i.e right side bromine atom) has an octet or not.

In simple words, we have to check whether the central Bromine (Br) atom is having 8 electrons or not.

As you can see from the above image, the central atom (i.e right side bromine atom) has 8 electrons. So it fulfills the octet rule and this bromine atom is also stable.

Step #6: Final step – Check the stability of lewis structure by calculating the formal charge on each atom

Now, you have come to the final step and here you have to check the formal charge on the bromine atoms (Br).

For that, you need to remember the formula of formal charge;

Formal charge = Valence electrons – Nonbonding electrons – (Bonding electrons)/2

• For Bromine:
  Valence electron = 7 (as it is in group 17)
  Nonbonding electrons = 6
  Bonding electrons = 2

So you can see above that the formal charge on both the bromine atoms are “zero”.

Hence, there will not be any change in the above structure and the above lewis structure of Br2 is the final stable structure only.

Each electron pair (:) in the lewis dot structure of Br2 represents the single bond ( | ). So the above lewis dot structure of Br2 can also be represented as shown below.

Related lewis structures for your practice:
Lewis Structure of BeCl2
Lewis Structure of CH3COO-
Lewis Structure of Acetone (C3H6O)
Lewis Structure of POCl3
Lewis Structure of HNO2

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