How do atoms become positive or negative ions?

Atoms become electrically charged ions through the process of ionization, which involves the gain or loss of electrons.

• Positive Ions (Cations): These are formed when a neutral atom loses one or more electrons. Because electrons carry a negative charge, their removal leaves the atom with a net positive charge.12
• Negative Ions (Anions): These are formed when a neutral atom gains one or more electrons. The addition of these negatively charged particles results in the atom having a net negative charge.12

This transfer of electrons often occurs during chemical reactions, such as when an electropositive element transfers electrons to an electronegative element to form an ionic bond. Ionization can also be triggered by external energy sources, including electric currents, high temperatures, or exposure to radiation like X-rays, which provide enough energy to eject electrons from neutral atoms.31