Atoms are at their most stable when their outermost energy level is either empty of electrons or filled with electrons.

How do you know if an ion is stable?

The octet rule states that an atom is most stable when there are eight electrons in its valence shell. Atoms with less than eight electrons tend to satisfy the duet rule, having two electrons in their valence shell. By satisfying the duet rule or the octet rule, ions are more stable.

Why are ions stable?

Why ions are more stable than atoms

On the other hand ions are formed when atoms lose or gain electrons . ... The atoms do not have completely filled outermost shell . This makes them unstable and cannot exist independently. So they lose or gain electrons to attain noble gas configuration and thus stability.