Will you write the names for the compound feo and fe2o3

FeO is Iron II Oxide. You identify that it's an ionic bond so it won't have any prefixes. By reverse criss-crossing the charges, Iron gets a 1+ charge, and Oxygen gets a 1- charge. Since you know that Oxygen has to have a 2- charge, you multiply the 1+ and 1- by 2 to fix their charges, thus giving Iron a 2+ charge and Oxygen a 2- charge.

Since Iron has a 2+ charge, it's roman numeral is II. So the answer is Iron II Oxide.

The other one is Iron III Oxide. By reverse criss-crossing the charges, Fe geta 3+ charge, and Oxygen gets a 2- charge. Since it's correct, the 3+ charge is the roman numeral. So, the answer is Iron III Oxide.