SeBr4 Lewis structure

SeBr₄ (selenium tetrabromide) has one selenium atom and four bromine atoms.

In SeBr₄ Lewis structure, there are four single bonds around the selenium atom, with four bromine atoms attached to it. Each bromine atom has three lone pairs, and the selenium atom has one lone pair.

Alternative method: Lewis structure of SeBr₄

Contents

Rough sketch

First, determine the total number of valence electrons

In the periodic table, selenium lies in group 16, and bromine lies in group 17.

Hence, selenium has six valence electrons and bromine has seven valence electrons.

Since SeBr₄ has one selenium atom and four bromine atoms, so…

Valence electrons of one selenium atom = 6 × 1 = 6
Valence electrons of four bromine atoms = 7 × 4 = 28

And the total valence electrons = 6 + 28 = 34

Learn how to find: Selenium valence electrons and Bromine valence electrons

Second, find the total electron pairs

We have a total of 34 valence electrons. And when we divide this value by two, we get the value of total electron pairs.

Total electron pairs = total valence electrons ÷ 2

So the total electron pairs = 34 ÷ 2 = 17

Third, determine the central atom

We have to place the least electronegative atom at the center.

Since selenium is less electronegative than chlorine, assume that the central atom is selenium.

Therefore, place selenium in the center and bromines on either side.

And finally, draw the rough sketch

SeBr4 Lewis Structure (Step 1) — Rough sketch of SeBr₄ Lewis structure | Image: Learnool

Lone pair

Here, we have a total of 17 electron pairs. And four Se — Br bonds are already marked. So we have to only mark the remaining thirteen electron pairs as lone pairs on the sketch.

Also remember that both (selenium and bromine) are the period 4 elements, so they can keep more than 8 electrons in their last shell.

Always start to mark the lone pairs from outside atoms. Here, the outside atoms are bromines.

So for each bromine, there are three lone pairs, and for selenium, there is one lone pair.

Mark the lone pairs on the sketch as follows:

SeBr4 Lewis Structure (Step 2) — Lone pairs marked, and got the stable Lewis structure of SeBr₄ | Image: Learnool

Formal charge

Use the following formula to calculate the formal charges on atoms:

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

For selenium atom, formal charge = 6 – 2 – ½ (8) = 0

For each bromine atom, formal charge = 7 – 6 – ½ (2) = 0

Here, both selenium and bromine atoms do not have charges, so no need to mark the charges.

Final structure

The final structure of SeBr₄ contains a central selenium atom linked to four bromine atoms through single covalent bonds. In this layout, the selenium atom utilizes an expanded valence shell to accommodate ten electrons, forming four bonding pairs and retaining one lone pair. Within this arrangement, each bromine atom successfully satisfies the octet rule by maintaining three lone pairs alongside its single shared bond. This configuration represents the most stable state for the neutral molecule because it results in a formal charge of zero for every atom involved. Therefore, this specific electronic distribution serves as the definitive and most accurate Lewis representation of selenium tetrabromide.

Next: BrCl₂^– Lewis structure

External video

How to Draw the Lewis Dot Structure for SeBr4: Selenium tetrabromide – YouTube • Wayne Breslyn

External links

Deep

Learnool.com was founded by Deep Rana, who is a mechanical engineer by profession and a blogger by passion. He has a good conceptual knowledge on different educational topics and he provides the same on this website. He loves to learn something new everyday and believes that the best utilization of free time is developing a new skill.