CF2S Lewis Structure in 6 Steps (With Images)

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

Let me explain the above image in short.

CF2S lewis structure has a Carbon atom (C) at the center which is surrounded by two Fluorine atoms (F) and one Sulfur atom (S). There is a double bond between the Carbon (C) & Sulfur (S) atom and a single bond between the Carbon (C) and Fluorine (F) atoms.

If you haven’t understood anything from the above image of CF2S lewis structure, then just stick with me and you will get the detailed step by step explanation on drawing a lewis structure of CF2S.

So let’s move to the steps of drawing the lewis structure of CF2S.

Steps of drawing CF2S lewis structure

Step 1: Find the total valence electrons in CF2S molecule

In order to find the total valence electrons in a CF2S molecule, first of all you should know the valence electrons present in carbon atom, sulfur 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 carbon, sulfur as well as fluorine using a periodic table.

Total valence electrons in CF2S molecule

→ Valence electrons given by carbon atom:

Carbon is group 14 element on the periodic table. ^[1] Hence the valence electrons present in carbon is 4.

You can see the 4 valence electrons present in the carbon 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.

→ Valence electrons given by sulfur atom:

Sulfur is a group 16 element on the periodic table. ^[3] 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.

Hence, 

Total valence electrons in CF2S molecule = valence electrons given by 1 carbon atom + valence electrons given by 1 sulfur atom + valence electrons given by 2 fluorine atoms = 4 + 6 + 7(2) = 24.

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 CF2S and it contains carbon atom (C), sulfur atom (S) and fluorine atoms (F).

You can see the electronegativity values of carbon atom (C), sulfur atom (S) and fluorine atoms (F) in the above periodic table.

If we compare the electronegativity values of carbon atom (C), sulfur atom (S) and fluorine atoms (F) then the carbon atom is less electronegative.

So here the carbon atom is the center atom and the sulfur & fluorine atoms are the outside atoms.

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

Now in the CF2S molecule, you have to put the electron pairs between the carbon (C) & sulfur (S) atom and between the carbon (C) & fluorine (F) atoms.

This indicates that these atoms are chemically bonded with each other in a CF2S 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 CF2S molecule, you can see that the outer atoms are sulfur atom and fluorine atoms.

These sulfur atom and 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 CF2S molecule.

The CF2S molecule has a total 24 valence electrons and all these valence electrons are used in the above sketch of CF2S.

Hence there are no remaining electron pairs to be kept on the central atom. 

So now let’s proceed to the next step.

Step 5: Check the octet on the central atom. If it does not have octet, then shift the lone pair to form a double bond or triple bond.

In this step, you have to check whether the central carbon atom (C) is stable or not.

In order to check the stability of the central carbon (C) atom, we have to check whether it is forming an octet or not.

Unfortunately, the carbon atom is not forming an octet here. Carbon has only 6 electrons and it is unstable.

Now to make this carbon atom stable, you have to shift the electron pair from the outer sulfur atom so that the carbon atom can have 8 electrons (i.e octet).

After shifting this electron pair, the central carbon atom will get 2 more electrons and thus its total electrons will become 8.

You can see from the above picture that the carbon atom is forming an octet as it has 8 electrons.

Now let’s proceed to the final step to check whether the lewis structure of CF2S is stable or not.

Step 6: 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 CF2S.

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 carbon (C) atom, sulfur (S) atom as well as fluorine (F) atoms present in the CF2S 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 CF2S molecule in the image given below.

For Carbon (C) atom:
Valence electrons = 4 (because carbon is in group 14)
Bonding electrons = 8
Nonbonding electrons = 0

For Sulfur (S) atom:
Valence electrons = 6 (because sulfur is in group 16)
Bonding electrons = 4
Nonbonding electrons = 4

For Fluorine (F) atom:
Valence electron = 7 (because fluorine is in group 17)
Bonding electrons = 2
Nonbonding electrons = 6

From the above calculations of formal charge, you can see that the carbon (C) atom, sulfur (S) atom as well as fluorine (F) atoms have a “zero” formal charge.

This indicates that the above lewis structure of CF2S is stable and there is no further change in the above structure of CF2S.

In the above lewis dot structure of CF2S, you can also represent each bonding electron pair (:) as a single bond (|). By doing so, you will get the following lewis structure of CF2S.

(Note: In step 5, if we had moved the electron pair from the fluorine atom, then there will be +1 and -1 charges on fluorine and sulfur respectively. But here we move the electron pair from the sulfur atom, which gives the more stable structure (having “zero” charges on all the atoms.))

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:

About author

Jay Rana

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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