* Octet Rule: The octet rule states that atoms tend to gain, lose, or share electrons to achieve a stable configuration with eight electrons in their outermost shell (valence shell).
* NF3 (Nitrogen trifluoride): Nitrogen has 5 valence electrons and forms three single bonds with fluorine, giving it a total of 8 electrons (6 from the bonds + 2 lone pairs). It follows the octet rule.
* CO2 (Carbon dioxide): Carbon has 4 valence electrons and forms double bonds with two oxygen atoms. This gives carbon 8 electrons and each oxygen 8 electrons (2 lone pairs + 6 from the bonds), satisfying the octet rule.
* OF2 (Oxygen difluoride): Oxygen has 6 valence electrons and forms two single bonds with fluorine. This gives oxygen 8 electrons (2 lone pairs + 6 from the bonds) and fluorine 8 electrons each, following the octet rule.
* Br2 (Bromine): Bromine is a diatomic molecule with each bromine atom sharing one electron with the other, resulting in each bromine having 8 electrons (4 lone pairs + 4 from the bond). This follows the octet rule.
* NO (Nitric oxide): Nitrogen has 5 valence electrons, and oxygen has 6. They form a double bond, giving nitrogen 7 electrons (2 lone pairs + 5 from the bonds) and oxygen 8 electrons. Nitrogen has only 7 electrons, making it an exception to the octet rule.
In summary: NO (Nitric oxide) is the molecule that does not follow the octet rule.
