So you have seen the above image by now, right?
Let me explain the above image in short.
TeF5- lewis structure has a Tellurium atom (Te) at the center which is surrounded by five Fluorine atoms (F). There are 5 single bonds between the Tellurium atom (Te) and each Fluorine atom (F). There are 3 lone pairs on all the Fluorine atoms (F) and 1 lone pair on the Tellurium atom (Te). The Tellurium atom has -1 formal charge.
If you haven’t understood anything from the above image of TeF5- ion lewis structure, then just stick with me and you will get the detailed step by step explanation on drawing a lewis structure of TeF5- ion.
So let’s move to the steps of drawing the lewis structure of TeF5- ion.
Steps of drawing TeF5 lewis structure
Step 1: Find the total valence electrons in TeF5- ion
In order to find the total valence electrons in a TeF5- ion, first of all you should know the valence electrons present in tellurium atom as well as fluorine 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 tellurium as well as fluorine using a periodic table.
Total valence electrons in TeF5- ion
→ Valence electrons given by tellurium atom:
Tellurium is a group 16 element on the periodic table. [1] Hence the valence electrons present in tellurium is 6.
You can see the 6 valence electrons present in the tellurium atom as shown in the above image.
→ Valence electrons given by fluorine atom:
Fluorine is group 17 element on the periodic table. [2] Hence the valence electron present in fluorine is 7.
You can see the 7 valence electrons present in the fluorine atom as shown in the above image.
Hence,
Total valence electrons in TeF5- ion = valence electrons given by 1 tellurium atom + valence electrons given by 5 fluorine atoms + 1 more electron is added due to 1 negative charge = 6 + 7(5) + 1 = 42.
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 ion is TeF5- ion and it contains tellurium atom (Te) and fluorine atoms (F).
You can see the electronegativity values of tellurium atom (Te) and fluorine atom (F) in the above periodic table.
If we compare the electronegativity values of tellurium (Te) and fluorine (F) then the tellurium atom is less electronegative.
So here the tellurium atom (Te) is the center atom and the fluorine atoms (F) are the outside atoms.
Step 3: Connect each atoms by putting an electron pair between them
Now in the TeF5 molecule, you have to put the electron pairs between the tellurium atom (Te) and fluorine atoms (F).
This indicates that the tellurium (Te) and fluorine (F) are chemically bonded with each other in a TeF5 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 atoms.
Here in the sketch of TeF5 molecule, you can see that the outer atoms are fluorine atoms.
These outer fluorine 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 TeF5- ion.
The TeF5- ion has a total 42 valence electrons and out of these, only 40 valence electrons are used in the above sketch.
So the number of electrons which are left = 42 – 40 = 2.
You have to put these 2 electrons on the central tellurium atom in the above sketch of TeF5 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 TeF5.
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 tellurium (Te) atom as well as fluorine (F) atoms present in the TeF5 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 TeF5 molecule in the image given below.
For Tellurium (Te) atom:
Valence electrons = 6 (because tellurium is in group 16)
Bonding electrons = 10
Nonbonding electrons = 2
For Fluorine (F) atom:
Valence electrons = 7 (because fluorine is in group 17)
Bonding electrons = 2
Nonbonding electrons = 6
Formal charge | = | Valence electrons | – | (Bonding electrons)/2 | – | Nonbonding electrons | ||
Te | = | 6 | – | 10/2 | – | 2 | = | -1 |
F | = | 7 | – | 2/2 | – | 6 | = | 0 |
From the above calculations of formal charge, you can see that the tellurium (Te) atom has -1 charge and the fluorine (F) atoms has 0 charge.
So let’s keep these charges on the respective atoms in the TeF5 molecule.
This overall -1 charge on the TeF5 molecule is represented in the image given below.
In the above lewis dot structure of TeF5- ion, you can also represent each bonding electron pair (:) as a single bond (|). By doing so, you will get the following lewis structure of TeF5- ion.
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:
SeBr2 Lewis Structure | HCP Lewis Structure |
TeF6 Lewis Structure | SeF5- Lewis Structure |
C2H3F Lewis Structure | NH2F Lewis Structure |
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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