TeBr4 (tellurium tetrabromide) has one tellurium atom and four bromine atoms.
In the TeBr4 Lewis structure, there are four single bonds around the tellurium atom, with four bromine atoms attached to it. Each bromine atom has three lone pairs, and the tellurium atom has one lone pair.
Alternative method: Lewis structure of TeBr4
Rough sketch
- First, determine the total number of valence electrons
In the periodic table, tellurium lies in group 16, and bromine lies in group 17.
Hence, tellurium has six valence electrons and bromine has seven valence electrons.
Since TeBr4 has one tellurium atom and four bromine atoms, so…
Valence electrons of one tellurium 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: Tellurium 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 tellurium is less electronegative than bromine, assume that the central atom is tellurium.
Therefore, place tellurium in the center and bromines on either side.
- And finally, draw the rough sketch
Lone pair
Here, we have a total of 17 electron pairs. And four Te — 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 tellurium is a period 5 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.
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 tellurium, there is one lone pair.
Mark the lone pairs on the sketch as follows:
Formal charge
Use the following formula to calculate the formal charges on atoms:
Formal charge = valence electrons – nonbonding electrons – ½ bonding electrons
For tellurium atom, formal charge = 6 – 2 – ½ (8) = 0
For each bromine atom, formal charge = 7 – 6 – ½ (2) = 0
Here, both tellurium and bromine atoms do not have charges, so no need to mark the charges.
Final structure
The final structure of TeBr4 contains a central tellurium atom linked to four bromine atoms through single covalent bonds. In this configuration, the tellurium atom utilizes an expanded valence shell to accommodate ten electrons, which consist of four bonding pairs and one lone pair. Within this layout, each of the four bromine atoms successfully satisfies the octet rule by retaining three lone pairs alongside its single shared bond. This arrangement represents the most stable state for the molecule because it results in a formal charge of zero for every atom involved. Accordingly, this specific electronic distribution serves as the definitive and most accurate Lewis representation of tellurium tetrabromide.
Next: AsF5 Lewis structure
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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.