HBr Lewis Structure in 6 Steps (With Images)

HBr lewis structure

So you have seen the above image by now, right?

Let me explain the above image in short.

HBr (hydrogen bromide) lewis structure has one Hydrogen atom (H) and one Bromine atom (Br) which contain a single bond between them. There are 3 lone pairs on the Bromine atom (Br).

If you haven’t understood anything from the above image of HBr (hydrogen bromide) lewis structure, then just stick with me and you will get the detailed step by step explanation on drawing a lewis structure of HBr.

So let’s move to the steps of drawing the lewis structure of HBr.

Steps of drawing HBr lewis structure

Step 1: Find the total valence electrons in HBr molecule

In order to find the total valence electrons in HBr (hydrogen bromide) molecule, first of all you should know the valence electrons present in a single hydrogen atom as well as bromine atom.
(Valence electrons are the electrons that are present in the outermost orbit of any atom.)

Here, I’ll tell you how you can easily find the valence electrons of hydrogen as well as bromine using a periodic table.

Total valence electrons in HBr molecule

→ Valence electrons given by hydrogen atom:

Hydrogen is group 1 element on the periodic table. [1] Hence the valence electron present in hydrogen is 1.

You can see that only 1 valence electron is present in the hydrogen atom as shown in the above image.

→ Valence electrons given by bromine atom:

Bromine is a group 17 element on the periodic table. [2] Hence the valence electrons present in bromine is 7.

You can see the 7 valence electrons present in the bromine atom as shown in the above image.

Hence, 

Total valence electrons in HBr molecule = valence electrons given by 1 hydrogen atom + valence electrons given by 1 bromine atom = 1 + 7 = 8.

Step 2: Select the central atom

For selecting the center atom, you have to remember that the atom which is less electronegative remains at the center.

Now the given molecule is HBr (hydrogen bromide). It has only two atoms, so you can select any of the atoms as a center atom.

HBr step 1

Let’s assume the bromine atom as a central atom (Because we have to keep hydrogen outside in any lewis structure).

Step 3: Connect each atoms by putting an electron pair between them

Now in the HBr molecule, you have to put the electron pairs between the hydrogen atom (H) and bromine atom (Br).

HBr step 2

This indicates that the hydrogen (H) atom and bromine (Br) atom are chemically bonded with each other in a HBr molecule.

Step 4: Make the outer atoms stable. Place the remaining valence electrons pair on the central atom.

Now in this step, you have to check the stability of the outer atom.

Here in the sketch of HBr molecule, we have assumed the bromine atom as a center atom. So the hydrogen is the outer atom.

Hence you have to make the hydrogen atom stable.

You can see in the below image that the hydrogen atom is forming a duplet and hence it is stable.

HBr step 3

Also, in step 1 we have calculated the total number of valence electrons present in the HBr molecule.

The HBr molecule has a total 8 valence electrons and out of these, only 2 valence electrons are used in the above sketch.

So the number of electrons which are left = 8 – 2 = 6.

You have to put these 6 electrons on the bromine atom in the above sketch of HBr molecule.

HBr step 4

Now let’s proceed to the next step.

Step 5: Check the octet on the central atom

In this step, you have to check whether the central bromine atom (Br) is stable or not.

In order to check the stability of the central bromine (Br) atom, we have to check whether it is forming an octet or not.

HBr step 5

You can see from the above picture that the bromine atom is forming an octet. That means it has 8 electrons.

And hence the central bromine atom is stable.

Now let’s proceed to the final step to check whether the lewis structure of HBr is stable or not.

Step 6: Check the stability of lewis structure

Now you have come to the final step in which you have to check the stability of lewis structure of HBr.

The stability of lewis structure can be checked by using a concept of formal charge.

In short, now you have to find the formal charge on hydrogen (H) atom as well as bromine (Br) atoms present in the HBr molecule.

For calculating the formal charge, you have to use the following formula;

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

You can see the number of bonding electrons and nonbonding electrons for each atom of HBr molecule in the image given below.

HBr step 6

For Hydrogen (H) atom:
Valence electron = 1 (because hydrogen is in group 1)
Bonding electrons = 2
Nonbonding electrons = 0

For Bromine (Br) atom:
Valence electron = 7 (because bromine is in group 17)
Bonding electrons = 2
Nonbonding electrons = 6

Formal charge=Valence electrons(Bonding electrons)/2Nonbonding electrons
H=12/20=0
Br=72/26=0

From the above calculations of formal charge, you can see that the hydrogen (H) atom as well as bromine (Br) atom has a “zero” formal charge.

This indicates that the above lewis structure of HBr is stable and there is no further change in the above structure of HBr.

In the above lewis dot structure of HBr, you can also represent each bonding electron pair (:) as a single bond (|). By doing so, you will get the following lewis structure of HBr.

Lewis structure of HBr

I hope you have completely understood all the above steps.

For more practice and better understanding, you can try other lewis structures listed below.

Try (or at least See) these lewis structures for better understanding:

CH3NH2 lewis structureSiO2 lewis structure
SiH4 lewis structureClO4- lewis structure
ClO- lewis structureNOCl lewis structure
About author

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. He is a founder of Pediabay and is passionate about helping students through his easily digestible explanations.

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