Definitions for "Octet rule"
elements of the 1 rst and 7 th main group in the periodic system have the tendency to attain 8 electrons in their outermost shell when they form chemical bonds.
There is reason to believe that it is the outer electrons which are involved to the greatest extent in chemical reactions. With the exception of the first shell, which is complete after two electrons, each atom seems able to hold a maximum of eight electrons in the outermost part of the atom. Using these two speculations it is tempting to postulate that when elements react, they do so in such a manner that each atom obtains an outer configuration consisting of eight electrons. This generalization is called the octet rule.
elements are more stable if they have an inert gas configuration