CH2 Lewis Structure in 5 Steps (With Images)

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

Let me explain the above image in short.

CH2 lewis structure has a Carbon atom (C) at the center which is surrounded by two Hydrogen atoms (H). There are 2 single bonds between the Carbon atom (C) and each Hydrogen atom (H). The Carbon atom (C) has 1 lone pair.

If you haven’t understood anything from the above image of CH2 lewis structure, then just stick with me and you will get the detailed step by step explanation on drawing a lewis structure of CH2 molecule.

So let’s move to the steps of drawing the lewis structure of CH2.

Steps of drawing CH2 lewis structure

Step 1: Find the total valence electrons in CH2 molecule

In order to find the total valence electrons in a CH2 molecule, first of all you should know the valence electrons present in carbon atom as well as hydrogen 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 as well as hydrogen using a periodic table.

Total valence electrons in CH2 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 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.

Hence, 

Total valence electrons in CH2 molecule = valence electrons given by 1 carbon atom + valence electrons given by 2 hydrogen atoms = 4 + 1(2) = 6.

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.

(Remember: If hydrogen is present in the given molecule, then always put hydrogen outside.)

Now here the given molecule is CH2 and it contains carbon atom (C) and hydrogen atoms (H).

You can see the electronegativity values of carbon atom (C) and hydrogen atom (H) in the above periodic table.

If we compare the electronegativity values of carbon (C) and hydrogen (H) then the hydrogen atom is less electronegative. But as per the rule we have to keep hydrogen outside.

So here the carbon atom (C) is the center atom and the hydrogen atoms (H) are the outside atoms.

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

Now in the CH2 molecule, you have to put the electron pairs between the carbon atom (C) and hydrogen atoms (H).

This indicates that the carbon (C) and hydrogen (H) are chemically bonded with each other in a CH2 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 CH2 molecule, you can see that the outer atoms are hydrogen atoms.

These outer hydrogen atoms are forming a duplet and hence they are stable. 

Also, in step 1 we have calculated the total number of valence electrons present in the CH2 molecule.

The CH2 molecule has a total 6 valence electrons and out of these, only 4 valence electrons are used in the above sketch.

So the number of electrons which are left = 6 – 4 = 2.

You have to put these 2 electrons on the central carbon atom in the above sketch of CH2 molecule.

Now let’s proceed to the next step.

Step 5: Check the formal charge

Now you have come to the final step in which you have to check the stability of lewis structure of CH2.

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 as well as hydrogen (H) atoms present in the CH2 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 CH2 molecule in the image given below.

For Carbon (C) atom:
Valence electrons = 4 (because carbon is in group 14)
Bonding electrons = 4
Nonbonding electrons = 2

For Hydrogen (H) atom:
Valence electron = 1 (because hydrogen is in group 1)
Bonding electrons = 2
Nonbonding electrons = 0

From the above calculations of formal charge, you can see that the carbon (C) atoms as well as hydrogen (H) atoms have a “zero” formal charge.

This indicates that the above lewis structure of CH2 is stable and there is no further change in the above structure of CH2.

In the above lewis dot structure of CH2, you can also represent each bonding electron pair (:) as a single bond (|). By doing so, you will get the following lewis structure of CH2.

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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