Element number 8 and a member of the
or Group 16 of the periodic table.
peroxide ion contains twoelectronsmore
than the oxygen molecule. These two electrons, according to themolecular
orbitaltheory, complete the two π*antibonding
orbitals. This has as result a weakening of thebond
strengthof the peroxide ion and a
greater length for the bond O-O : Li2O2130
pm to BaO2147
pm. Furthermore, the peroxide ion isdiamagnetic.