In terms of ionic compounds an oxide contain the oxide ion (O2-) Which is a single oxygen atom with a 2- charge. A peroxide contains the peroxide ion (O 22-) which is a particle of two oxygen atoms bonded together and has a 2- charge. Unlike most normal oxides, peroxides tend to be oxidizers or at the very least, unstable. A superoxide contains the superoxide ion (O 2-) which consists of two oxygen atoms bonded together and has a 1- charge. This ion is even more strongly oxidizing than the peroxide ion. In covalent compounds oxides are substances that contain oxygen in the 2- oxidation state and not bonded ot other oxygen atoms. Peroxide contain a peroxide group (O 2) in which each oxygen atom is bonded to the other oxygen an to another atom, typically carbon or hydrogen. IN this case oxygen is in the 1- oxidation state.