Lewis Structure of P2 (With 6 Simple Steps to Draw!)

Lewis Structure of P2

Ready to learn how to draw the lewis structure of P2?


Here, I have explained 6 simple steps to draw the lewis dot structure of P2 (along with images).

So, if you are ready to go with these 6 simple steps, then let’s dive right into it!

Lewis structure of P2 contains one triple bond between both the Phosphorus (P) atoms. And both the Phosphorus atoms have one lone pair on it.

Let’s draw and understand this lewis dot structure step by step.

(Note: Take a pen and paper with you and try to draw this lewis structure along with me. I am sure you will definitely learn how to draw lewis structure of P2).

6 Steps to Draw the Lewis Structure of P2

Step #1: Calculate the total number of valence electrons

Here, the given molecule is P2. In order to draw the lewis structure of P2, first of all you have to find the total number of valence electrons present in the P2 molecule.
(Valence electrons are the number of electrons present in the outermost shell of an atom).

So, let’s calculate this first.

Calculation of valence electrons in P2

  • For Phosphorus: 

Phosphorus is a group 15 element on the periodic table. [1]

Hence, the valence electrons present in phosphorus is 5 (see below image).

Hence, total number of Valence electrons in P2 molecule = 5(2) = 10

Step #2: Select the center atom

While selecting the atom, you have to put the least electronegative atom at the center. 

But here in the P2 molecule, both the atoms are same. So you can consider any of the atoms as a center atom.

step 1

So, let’s assume that the phosphorus which is on the right side is the central atom.

Step #3: Put two electrons between the atoms to represent a chemical bond

Now in the above sketch of P2 molecule, put the two electrons (i.e electron pair) between both the phosphorus atoms to represent a chemical bond between them.

step 2

These pair of electrons present between the Phosphorus (P) atoms form a chemical bond, which bonds both the phosphorus atoms with each other in a P2 molecule.

Step #4: Complete the octet (or duplet) on outside atom. If the valence electrons are left, then put the valence electrons pair on the central atom

Don’t worry, I’ll explain!

In the Lewis structure of P2, we have just assumed the right side phosphorus atom as a central atom and so the left side phosphorus atom is an outer atom.

So now, we have to complete the octet on this left side phosphorus atom.

step 3

Now, you can see in the above image that the outer phosphorus atom forms an octet.

Also, only 8 valence electrons of P2 molecule are used in the above structure.

But there are total 10 valence electrons in P2 molecule (as calculated in step #1).

So the number of electrons left to be kept on the central atom = 10 – 8 = 2.

So let’s keep these two electrons (i.e electron pair) on the central atom (i.e right side phosphorus atom).

step 4

Now, let’s move to the next step.

Step #5: Check whether the central atom has octet or not. If it does not have an octet, then move the electron pair from the outer atom to form a double bond or triple bond

In this step, we have to check whether the central atom (i.e right side phosphorus atom) has an octet or not.

In simple words, we have to check whether this Phosphorus (P) atom is having 8 electrons or not.

step 5

As you can see from the above image, this right side phosphorus atom has only 4 electrons. So it does not fulfill the octet rule.

Now, in order to fulfill the octet of this phosphorus atom, we have to move the electron pair from the outer atom (i.e left side phosphorus atom) to form a double bond.

step 6

Still, the octet of phosphorus atom is not fulfilled as it has only 6 electrons.

So again moving the electron pair from the outer phosphorus atom, we will get the following structure.

step 7

Now you can see from the above image that the phosphorus atom has 8 electrons. So it fulfills the octet rule and it is stable.

Step #6: Final step – Check the stability of lewis structure by calculating the formal charge on each atom

Now, you have come to the final step and here you have to check the formal charge on the phosphorus atoms (P).

For that, you need to remember the formula of formal charge;

Formal charge = Valence electrons – Nonbonding electrons – (Bonding electrons)/2

step 8
  • For Phosphorus:
    Valence electrons = 5 (as it is in group 15)
    Nonbonding electrons = 2
    Bonding electrons = 6
Formal charge=Valence electronsNonbonding electrons(Bonding electrons)/2

So you can see above that the formal charge on both the phosphorus atoms are “zero”.

Hence, there will not be any change in the above structure and the above lewis structure of P2 is the final stable structure only.

Each electron pair (:) in the lewis dot structure of P2 represents the single bond ( | ). So the above lewis dot structure of P2 can also be represented as shown below.

p2 lewis structure

Related lewis structures for your practice:
Lewis Structure of IBr2-
Lewis Structure of PI3
Lewis Structure of NOBr
Lewis Structure of ClF2-
Lewis Structure of ClF4- 

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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. With a desire to make learning accessible for everyone, he founded Knords Learning, an online learning platform that provides students with easily understandable explanations.

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