How can an element attain a stable electronic configuration?

Hint:Before solving this question, first we have to understand the basic definitions of atoms. Atoms are generally the most fundamental and the smallest part which can exist of an element.

Complete answer:
According to the octet configuration as the name suggests Oct means eight the atom has eight electrons in the outermost orbit. Valence shell is the outermost shell of every element and valence electrons are the number of electrons which are present in the valence shell of the electrons. To have an inert configuration, an element must follow the octet rule. There are some exceptions to it.
To attain the inert configuration of the stable electronic configuration an element either lose or gain electrons. The element can form a covalent bond by sharing the electrons to attain a stable electronic configuration.

Additional information:
Limitations of octet rule:
As hydrogen and helium both have only one and two electrons respectively in their outermost shell it is impossible for them to have eight electrons in their outermost shell. So, there are many compounds which have less than eight electrons in their outermost shell but are still stable.
Similarly, there are many compounds which have more than eight electrons in their outermost shell but are still stable.

Note:
The octet rule is based on the concept that electronic configuration of the noble gases is most stable and they have eight electrons in their outermost orbital so every element should attain the similar electronic configuration to become stable.