Súrefnisjóna

A súrefnisjóna, also known as an oxide ion, is an atom of oxygen that has gained two electrons, resulting in a net negative charge of -2. In its atomic form, oxygen has an atomic number of 8, meaning it has 8 protons and typically 8 electrons. Oxygen's electron configuration is 2, 6. To achieve a stable electron configuration, similar to that of the nearest noble gas (neon), oxygen needs to gain two more electrons to fill its outermost shell. When it gains these electrons, it becomes an anion with the chemical formula O^2-.

Súrefnisjóna are commonly found in ionic compounds, such as metal oxides. For example, in sodium oxide (Na2O), the sodium atoms lose electrons to become positively charged sodium ions (Na+), while the oxygen atom gains two electrons to become a súrefnisjóna (O^2-). The electrostatic attraction between these oppositely charged ions holds the compound together. These ions play a crucial role in many chemical reactions and geological processes. The stability of the súrefnisjóna is a driving force for many oxidation-reduction reactions.