Which of the following describes the specific iron ion in the compound, FeO?

Ferride ion

Iron (I) ion

Iron (II) ion

Ferride (I) ion

Here we have to choose the specific iron ion preset in the compound FeO among the given ions.

The iron ion present in FeO is iron (II) ion.

The compound FeO is a neutral compound. Where the anion is oxide ion (O²⁻) thus the cation should also contain two unit positive charge. Thus Fe²⁺. Hence, the iron ion is Fe (II) ion.

The ferride ion means Fe²⁻ ion which cannot be present in FeO as the anion is already present which is O²⁻.

The iron (I) ion means iron present in + 1 state, then to neutralize the compound 2 iron (I) is needed but in compound FeO there is only one iron present. Thus it cannot be iron (I) ion.

The ferride (I) ion means Fe¹⁻, which cannot be the state of the iron in FeO as there already present an anion which is O²⁻ ion.