SHF 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.

SHF lewis structure has an Sulfur atom (S) at the center which is surrounded by one Hydrogen atom (H) and one Fluorine atom (F). There is a single bond between the Hydrogen (H) & Sulfur (S) atom as well as between the Sulfur (S) & Fluorine (F) atom.

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

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

Steps of drawing SHF lewis structure

Step 1: Find the total valence electrons in SHF molecule

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

Total valence electrons in SHF molecule

→ Valence electrons given by sulfur atom:

Sulfur is a group 16 element on the periodic table. ^[1] 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.

→ Valence electrons given by hydrogen atom:

Hydrogen is group 1 element on the periodic table. ^[2] Hence the valence electron present in hydrogen is 1.

You can see that only 1 valence electron is present in the hydrogen atom as shown in the above image.

→ Valence electrons given by fluorine atom:

Fluorine is group 17 element on the periodic table. ^[3] 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 SHF molecule = valence electrons given by 1 hydrogen atom + valence electrons given by 1 sulfur atom + valence electrons given by 1 fluorine atom = 1 + 6 + 7 = 14.

Step 2: Prepare the rough sketch

To draw the rough sketch of a SHF molecule, just look at its chemical formula only. You can see that there is an sulfur atom (S) at the center and it is surrounded by hydrogen atom (H) and fluorine atom (F) on either side.

So let’s draw a rough sketch for the same.

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

Now in the SHF molecule, you have to put the electron pairs between the hydrogen (H) & sulfur (S) atom and between the sulfur (S) & fluorine (F) atom.

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

These hydrogen and fluorine atoms are forming a duplet and octet respectively and hence they are stable. 

Also, in step 1 we have calculated the total number of valence electrons present in the SHF molecule.

The SHF molecule has a total 14 valence electrons and out of these, only 10 valence electrons are used in the above sketch.

So the number of electrons which are left = 14 – 10 = 4.

You have to put these 4 electrons on the central sulfur atom in the above sketch of SHF molecule.

Now let’s proceed to the next step.

Step 5: Check the octet on the central atom

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

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

You can see from the above picture that the sulfur atom is forming an octet. That means it has 8 electrons.

And hence the central sulfur atom is stable.

Now let’s proceed to the final step to check whether the lewis structure of SHF 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 SHF.

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 hydrogen (H) atom, sulfur (S) atom as well as fluorine (F) atom present in the SHF 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 SHF molecule in the image given below.

For Hydrogen (H) atom:
Valence electron = 1 (because hydrogen is in group 1)
Bonding electrons = 2
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

Formal charge	=	Valence electrons	–	(Bonding electrons)/2	–	Nonbonding electrons
H	=	1	–	2/2	–	0	=	0
S	=	6	–	4/2	–	4	=	0
F	=	7	–	2/2	–	6	=	0

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

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

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

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:

SeS3 Lewis Structure	IBr5 Lewis Structure
AsI3 Lewis Structure	SbF6- Lewis Structure
SbCl3 Lewis Structure	C2H4F2 Lewis Structure