How is the formation of ions related to electron configuration?

The formation of ions is directly related to electron configuration as atoms gain or lose electrons to achieve a stable configuration.

In more detail, electron configuration refers to the arrangement of electrons in the energy levels, sublevels and orbitals of an atom. The most stable electron configuration is one where the atom's outer energy level is full, often with eight electrons, known as the octet rule. This is because a full outer energy level is the most stable state for an atom, and atoms will always try to achieve this state.

Atoms form ions in an attempt to reach this stable electron configuration. If an atom has a nearly full outer energy level, it will try to gain electrons to fill it, forming a negatively charged ion, or anion. For example, chlorine has seven electrons in its outer energy level and needs one more to have a full outer level. It can gain an electron from another atom to become a chloride ion, Cl-.

On the other hand, if an atom has just a few electrons in its outer energy level, it will try to lose these electrons to expose the full level beneath, forming a positively charged ion, or cation. For instance, sodium has one electron in its outer energy level. It can lose this electron to expose the full level beneath and become a sodium ion, Na+.

In both cases, the formation of ions is directly related to the atom's electron configuration. The atom will gain or lose electrons in order to achieve a more stable state, which is a full outer energy level. This process is fundamental to chemical reactions and the formation of compounds.