Why do atoms gain or lose electrons?

Atoms gain or lose electrons primarily to achieve stability, which is often in the context of attaining a full outer electron shell. Most elements strive to reach a stable electronic configuration, similar to that of the noble gases, which have full outer shells. This can be accomplished by losing, gaining, or sharing electrons through various chemical processes.

When an atom has a nearly full outer shell, it tends to gain electrons to fill that shell, while atoms with nearly empty outer shells will tend to lose electrons. This pursuit of achieving a stable electron configuration typically results in the formation of ions, thereby affecting the atom's chemical reactivity and interactions with other atoms.

While it is true that in the process of gaining or losing electrons, atoms may become charged, this phenomenon is a consequence of achieving stability rather than the primary goal itself. Additionally, while bonding with other atoms may occur as a result of gaining or losing electrons, it is not the ultimate reason for the action. The production of energy can occur in chemical reactions, but it is not the driving force behind an atom's decision to gain or lose electrons. Thus, stability stands as the central rationale for these electron interactions.