For elements which have more than two oxoanions,
- per------ate is used for the oxoanions containing the central element in a higher oxidation state than the -ate ion.
As the examples below show, per----ate oxoanions always have a larger number of oxygen atoms per unit charge than the corresponding -ate oxoanion.
Usually the per---ate has more oxygens than the -ate ion and the same charge.
| MnO4– permanganate | ClO4– perchlorate |
| | ClO3– chlorate |
| | ClO2– chlorite |
| | ClO– hypochlorite |
- hypo----ite is used for oxygen-containing anions having a lower oxidation state for the central atom the -ite ion
Commonly hypo----ite ions have fewer oxygen atoms but the same charge as the corresponding -ite ion. In all cases these have fewer oxygen atoms per unit charge.