O₂ ^-2

C₂O₄ ^-2

Zn ⁺²

Zinc ion

C₄H₄O₆ ^-2

Hg₂ ⁺²

Cd ⁺²

Dichromate

Tin (II) ion

Iron (III) ion

Fe⁺³

^{Used to be referred to as Ferric ion.}

P^-3

Sn⁺⁴

This ion is named according to the Stock system of naming using Roman numerals after the element name to indicate the charge out of more than one possible.

This ion used to be named in the classical system by adding -ic to the latin name, hence, Stannic ion.  Sn⁺² would have been named Stannous ion