Lewis structure of SiBr4

The information on this page is ✔ fact-checked.

The Lewis structure of SiBr₄ contains four single bonds, with silicon in the center, and four bromines on either side. There are three lone pairs on each bromine atom, and the silicon atom does not have any lone pair.

Steps

By using the following steps, you can easily draw the Lewis structure of SiBr₄.

#1 Draw skeleton
#2 Show chemical bond
#3 Mark lone pairs
#4 Calculate formal charge and check stability (if octet is already completed on central atom)

Let’s one by one discuss each step in detail.

#1 Draw skeleton

In this step, first calculate the total number of valence electrons. And then, decide the central atom.

• Let’s calculate the total number of valence electrons

We know that… silicon is a group 14 element and bromine is a group 17 element. Hence, silicon has four valence electrons and bromine has seven valence electrons.

Now SiBr₄ has one silicon atom and four bromine atoms.

So the total number of valence electrons = valence electrons of silicon atom + (valence electrons of bromine atom × 4)

Therefore, the total number of valence electrons = 4 + 28 = 32

• Now decide the central atom

The atom with the least electronegative value is placed at the center. By looking at the periodic table, we get the electronegativity values for silicon and bromine as follows:

Electronegativity value of silicon = 2.58
Electronegativity value of bromine = 2.96

Obviously, silicon is less electronegative than bromine. Hence, assume that silicon is the central atom.

So now, put silicon in the center and bromines on either side. And draw the rough skeleton structure for the Lewis structure of SiBr₄ something like this:

Also read: How to draw Lewis structure of CH₃NO₂ (5 steps)

#2 Show chemical bond

Place two electrons between the atoms to show a chemical bond. Since silicon is surrounded by four bromines, use eight electrons to show four chemical bonds as follows:

Also read: How to draw Lewis structure of AsF₃ (4 steps)

#3 Mark lone pairs

As calculated earlier, we have a total of 32 valence electrons. And in the above structure, we have already used eight valence electrons. Hence, twenty-four valence electrons are remaining.

Two valence electrons represent one lone pair. So twenty-four valence electrons = twelve lone pairs.

Note that silicon is a period 3 element, so it can keep more than 8 electrons in its last shell. And bromine is a period 4 element, so it can keep more than 8 electrons in its last shell.

Also, make sure that you start marking these lone pairs on outside atoms first. And then, on the central atom.

The outside atoms are bromines, so each bromine will get three lone pairs. And the central atom (silicon) will not get any lone pair, because all twelve lone pairs are used.

So the Lewis structure of SiBr₄ looks something like this:

In the above structure, you can see that the octet is completed on the central atom (silicon), and also on the outside atoms. Therefore, the octet rule is satisfied.

After completing the octet, one last thing we need to do is, calculate the formal charge and check the stability of the above structure.

Also read: How to draw Lewis structure of NO₂Cl (5 steps)

#4 Calculate formal charge and check stability

The following formula is used to calculate the formal charges on atoms:

Formal charge = valence electrons – nonbonding electrons – ½ bonding electrons

Collect the data from the above structure and then, write it down below as follows:

• For silicon atom

Valence electrons = 4
Nonbonding electrons = 0
Bonding electrons = 8

Formal charge = 4 – 0 – ½ (8) = 0

• For each bromine atom

Valence electrons = 7
Nonbonding electrons = 6
Bonding electrons = 2

Formal charge = 7 – 6 – ½ (2) = 0

Mention the formal charges of atoms on the structure. So the Lewis structure of SiBr₄ looks something like this:

In the above structure, you can see that the formal charges of both (silicon and bromine) are zero. Therefore, this is the stable Lewis structure of SiBr₄.

And each horizontal line drawn in the above structure represents a pair of bonding valence electrons.

📝 Your feedback matters. Visit our contact page.

Related

• Lewis structure of CH₃NO₂
• Lewis structure of AsF₃
• Lewis structure of NO₂Cl
• Lewis structure of BeCl₂
• Lewis structure of CH₂N₂

External links

• SiBr4 Lewis Structure in 6 Steps (With Images) – Pediabay
• SiBr4 Lewis Structure, Geometry, Hybridization, and Polarity – Techiescientist
• In the Lewis structure for SiBr₄, Si has _____ bond(s) and _____ lone pair(s) while each Br has _____ bond(s) and _____ lone pair(s) – Homework.Study.com
• Determine the Lewis Dot Structure for the silicon tetrabromide molecule, SiBr4 – Pearson
• Draw the Lewis structure for SiBr4 – Chegg
• Draw the Lewis dot structure of SiBr₄ – Quizlet
• What is the Lewis structure of SiBr4? – Answers
• Provide the best Lewis structure for SiBr4 and sketch the 3D representation of the molecule indicating the electron and molecular geometry – Course Hero
• Write the Lewis structure for SiBr4 and check those statements which are correct – Numerade