Cl (chlorine) has one chlorine atom. In the lewis structure of Cl, there are three lone pairs and one unpaired electron on the chlorine atom.
Here’s how you can draw the Cl lewis structure step by step.
Step #1: draw sketch
Step #2: mark lone pairs
Step #3: mark charges (if there are)
Let’s break down each step in detail.
#1 Draw Sketch
- First, determine the total number of valence electrons
In the periodic table, chlorine lies in group 17. Hence, chlorine has seven valence electrons.
Since Cl has one chlorine atom, so…
Valence electrons of one chlorine atom = 7 × 1 = 7
So the total valence electrons = 7
- Second, find the total electron pairs
We have a total of 7 valence electrons. And when we divide this value by two, we get the value of total electron pairs.
But 7 can not be divided by two. Hence, there are a total of 3 electron pairs and one unpaired electron.
- Third, determine the central atom
There is only one atom present here, so assume that the central atom is chlorine.
- And finally, draw the rough sketch
#2 Mark Lone Pairs
Here, we have 3 electron pairs and one unpaired electron. So we have to mark these three electron pairs and one unpaired electron 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. But here, there is no outside atom. So for chlorine, there are three lone pairs and one unpaired electron.
Mark the lone pairs on the sketch as follows:
#3 Mark Charges
Use the following formula to calculate the formal charges on atoms:
Formal charge = valence electrons – nonbonding electrons – ½ bonding electrons
For chlorine atom, formal charge = 7 – 7 – ½ (0) = 0
Here, the chlorine atom does not have charge, so no need to mark the charge.
In the above structure, you can see that the central atom (chlorine) doesn’t form an octet. But in Cl lewis structure, chlorine has an exception that it does not require eight electrons to form an octet. So no need to worry about the octet rule here.
Therefore, this structure is the stable lewis structure of Cl.
Next: Lewis Structure of Cl–