SBr4 Lewis Structure in 5 Steps (With Images)

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

Let me explain the above image in short.

SBr4 lewis structure has a Sulfur atom (S) at the center which is surrounded by four Bromine atoms (Br). There are 4 single bonds between the Sulfur atom (S) and each Bromine atom (Br). There is 1 lone pair on the Sulfur atom (S) and 3 lone pairs on all the four Bromine atoms (Br).

If you haven’t understood anything from the above image of SBr4 lewis structure, then just stick with me and you will get the detailed step by step explanation on drawing a lewis structure of SBr4.

So let’s move to the steps of drawing the lewis structure of SBr4.

Steps of drawing SBr4 lewis structure

Step 1: Find the total valence electrons in SBr4 molecule

In order to find the total valence electrons in SBr4 molecule, first of all you should know the valence electrons present in sulfur 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 sulfur as well as bromine using a periodic table.

Total valence electrons in SBr4 molecule

→ Valence electrons given by sulfur atom:

Sulfur is a group 16 element on the periodic table. ^[1] Hence the valence electrons present in sulfur is 6.

You can see the 6 valence electrons present in the sulfur 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 SBr4 molecule = valence electrons given by 1 sulfur atom + valence electrons given by 4 bromine atoms = 6 + 7(4) = 34.

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 here the given molecule is SBr4 and it contains sulfur atom (S) and bromine atoms (Br).

You can see the electronegativity values of sulfur atom (S) and bromine atom (Br) in the above periodic table.

If we compare the electronegativity values of sulfur (S) and bromine (Br) then the sulfur atom is less electronegative.

So here the sulfur atom (S) is the center atom and the bromine atoms (Br) are the outside atoms.

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

Now in the SBr4 molecule, you have to put the electron pairs between the sulfur atom (S) and bromine atoms (Br).

This indicates that the sulfur (S) and bromine (Br) are chemically bonded with each other in a SBr4 molecule.

Step 4: Make the outer atoms stable

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

Here in the sketch of SBr4 molecule, you can see that the outer atoms are bromine atoms.

These outer bromine atoms are forming an octet and hence they are stable.

Also, in step 1 we have calculated the total number of valence electrons present in the SBr4 molecule.

The SBr4 molecule has a total 34 valence electrons and out of these, only 32 valence electrons are used in the above sketch.

So the number of electrons which are left = 34 – 32 = 2.

You have to put these 2 electrons on the central sulfur atom in the above sketch of SBr4 molecule.

Now let’s proceed to the next step.

Step 5: 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 SBr4.

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 sulfur (S) atom as well as bromine (Br) atoms present in the SBr4 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 SBr4 molecule in the image given below.

For Sulfur (S) atom:
Valence electrons = 6 (because sulfur is in group 16)
Bonding electrons = 8
Nonbonding electrons = 2

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)/2	–	Nonbonding electrons
S	=	6	–	8/2	–	2	=	0
Br	=	7	–	2/2	–	6	=	0

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

This indicates that the above lewis structure of SBr4 is stable and there is no further change in the above structure of SBr4.

In the above lewis dot structure of SBr4, you can also represent each bonding electron pair (:) as a single bond (|). By doing so, you will get the following lewis structure of SBr4.

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:

CFCl3 Lewis Structure	NCl2- Lewis Structure
AsCl5 Lewis Structure	COBr2 Lewis Structure
GeF4 Lewis Structure	Cl2O2 Lewis Structure