What is the chemical formula for the peroxide ion?

The peroxide ion is characterized by having two oxygen atoms bonded together and carrying a net charge of -2. This unique structure can be represented by the formula O2(2-). In this ion, each oxygen atom shares one pair of electrons, which results in a covalent bond, while the overall ion has gained two additional electrons, contributing to its -2 charge.

Understanding this ion is important in various chemical reactions, particularly in organic chemistry and in the study of oxidizing agents. The other options provided do not represent the peroxide ion: O2 refers to molecular oxygen, H2O2 is hydrogen peroxide (not an ion), and OH(-) represents the hydroxide ion, which has a different composition and charge. Therefore, O2(2-) is the correct representation of the peroxide ion.