pentaoxide

As nouns the difference between superoxide and pentaoxide

is that superoxide is while pentaoxide is variant of pentoxide.

As nouns the difference between peroxide and pentaoxide

is that peroxide is a divalent radical or anion containing two oxygen atoms linked by a covalent bond; any substance containing this group which yields hydrogen peroxide when treated with an acid while pentaoxide is variant of pentoxide.

As a verb peroxide

is to treat (something) with hydrogen peroxide, especially hair in order to bleach it.