What are the exceptions to octet rule with odd number electrons?
Molecules with an odd number of electrons are exceptions to the octet rule because there is no way for all atoms to achieve an even-numbered octet.
Consider nitrogen monoxide, NO. It has 11 valence electrons. There is no way that both atoms can get an octet.
NO₂ and ClO₂ are other molecules with odd numbers of valence electrons
Free radicals such as CH₃· and HO· are odd-electron species that formed during reactions by removing an atom such as H with its shared electron from stable molecules such as CH₄ and H₂O.