Cl2 Lewis structure

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Cl2 Lewis Structure
Cl2 Lewis structure

Cl2 (chlorine) has two chlorine atoms.

In the Cl2 Lewis structure, there is a single bond between the two chlorine atoms, and on each chlorine atom, there are three lone pairs.


Use these steps to correctly draw the Cl2 Lewis structure:

#1 First draw a rough sketch
#2 Mark lone pairs on the atoms
#3 Calculate and mark formal charges on the atoms, if required

Let’s discuss each step in more detail.

#1 First draw a rough sketch

  • First, determine the total number of valence electrons
Periodic table

In the periodic table, chlorine lies in group 17. Hence, chlorine has seven valence electrons.

Since Cl2 has two chlorine atoms, so…

Valence electrons of two chlorine atoms = 7 × 2 = 14

So the total valence electrons = 14

  • Second, find the total electron pairs

We have a total of 14 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 = 14 ÷ 2 = 7

  • Third, determine the central atom

Here, there are only two atoms and both atoms are chlorine, so we can assume any one as the central atom.

Let’s assume that the central atom is right chlorine.

  • And finally, draw the rough sketch
Cl2 Lewis Structure (Step 1)
Rough sketch of Cl2 Lewis structure

#2 Mark lone pairs on the atoms

Here, we have a total of 7 electron pairs. And one Cl — Cl bond is already marked. So we have to only mark the remaining six electron pairs as lone pairs on the sketch.

Also remember that chlorine is a period 3 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 atom is left chlorine.

So for each chlorine, there are three lone pairs.

Mark the lone pairs on the sketch as follows:

Cl2 Lewis Structure (Step 2)
Lone pairs marked, and got the stable Lewis structure of Cl2

#3 Calculate and mark formal charges on the atoms, if required

Use the following formula to calculate the formal charges on atoms:

Formal charge = valence electrons – nonbonding electrons – ½ bonding electrons

For each chlorine atom, formal charge = 7 – 6 – ½ (2) = 0

Here, both chlorine atoms do not have charges, so no need to mark the charges.

In the above structure, you can see that the central atom (right chlorine) forms an octet. And the outside atom (left chlorine) also forms an octet. Hence, the octet rule is satisfied.

Therefore, this structure is the stable Lewis structure of Cl2.

Next: HF Lewis structure

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