What Is The Octet Rule In Chemistry? – Explanation And Examples

The octet rule is the rule that describes the atoms of the main group elements tends to combine for balance shell with such approach that each atom has eight valence electrons. They tend to have the same electronic configuration as a noble gas. Example of these elements are carbon (C), Nitrogen (N), Oxygen (O), and the halogens and also the metals such as sodium (Na) or magnesium (Mg).

It is the rule of nature that all the things in this universe tend to get balanced. Similarly, few gases known as Nobles Gases have balanced valence shells. And all other elements try to get balanced valence shells.

In this article, we will describe the octet rule and its background along with examples, so read the article until the end.


In 1916, an American physical chemist, Gilbert N. Lewis, created his cubical atom model and the rule of eight. His theory describes that the atoms tend to combine to get the stable state and that is achieved by 8 valence electrons.

The Octet Rule

According to this rule, an atom is considered to be in the stable state if it possess eight electrons in its valence shells, and due to these eight electrons, it is known as octet rule.

This stability is achieved either by sharing own electron or other element’s electron. An atom continues sharing until it gets eight electrons or in other words if the octet is formed. Valence shell is known as the outer shell of an atom and if any atom is successful in achieving the 8 electrons then we say that the atom is stable and the atom has the same configuration of electrons as a Noble Gas.

In the periodic table, the zero group containing the elements helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn) are known as noble gases. These are called as noble because they are rarely found on the earth and there outer most shell forms octet and they are the most stable therefore they were believed not to react with any other element.

Other than these, all the elements are not stable. So if they have more electrons they lose them by sharing with those elements that have fewer electrons. And if an element has less electron it will try to gain the electron by sharing to get stable. Briefly, we can say that all the elements share their electrons until the octet is formed in the valence shell as that of noble gases.

Sodium And Chlorine

carbon dioxide

Chlorine atom possess 7 valence electrons and if it has to fulfill the octet rule then it requires one more electron. Whereas, sodium atom has only 1 electron in its valence shell and it requires 7 electrons to fulfill octet rule.

If they are combined the chlorine atom removes the one valence electron from sodium and completes its 8 electrons. Now it has the configuration similar to Argon noble gas. Now there is no electron left in the valence shell of sodium atom and at this stage, its configuration is similar to neon noble gas

Carbon Dioxide

Sodium and chlorine

Carbon dioxide is generated through the bonding of 1 carbon atom and 2 oxygen atoms i.e. CO2. Carbon has four electrons in its shell and to fulfill the octet rule it requires four more electrons.  Whereas oxygen has six valence electrons and to fulfill the octet rule it would need 2 more electrons.

When carbon and oxygen atoms are combined then Carbon shares its 2 valence electrons with 1 oxygen atom and the other two valence electrons with the second oxygen. Oxygen then, in turn, shares two of its electrons with the carbon atom. This type of sharing is known as covalent bonding because in this no atom losses its electron and all the atoms allow each other to share their electrons to react the octet.

I hope you liked my post about octet rule and if you have any query then write it down in the comments section.

By profession, I'm a software engineer. Everyone has one strong driving force in self that let one evolve above boundaries, my passion is content creation. Following my ambition, I am founder and CEO at TapeDaily with aim of providing high-quality content and the ultimate goal of reader satisfaction. Consistent improvement has always been my priority. The spark with time ignites more and more and recognized me as one of the leading SEO experts in UAE. I've successfully delivered vast improvements in search engine rankings across a variety of clients and sectors, including property and real estate. TapeDaily accomplishes all of your daily problems with best solutions. The team is comprised of passionate writers with the particular interest and expertise in respective categories to meet the objective of quality over quantity to provide you spectacular articles of your interest. "I believe in hidden skills and passing positive energy, a strong leader definitely builds an efficacious team." - Shahid Maqbool

Related Articles

How To Make a Dog Throw Up? If Your Dog Has Eaten Some Bad Thing

Sometimes your dog swallowed a toxic object such as chemicals or...



Please enter your comment!
Please enter your name here

Same Category

How To Make a Dog Throw Up? If Your Dog Has Eaten Some Bad Thing

Sometimes your dog swallowed a toxic object such as...

Longest Living Dog Breeds: Top 25 Dog Breeds With Longer Life Span

Longest Living Dog: In comparison with human beings life...

How To Get Rid of Flies? Homemade Fly Spray Recipe For Home and Animals

How To Get Rid of Flies? People buy expensive...

Stay in touch!

Follow our Instagram