Question

Tell the ionic configuration of fe2o3 (detail)

Answer 1

FeOFeOIs called "Iron(II) oxide ".
Fe2O3FeX2OX3Is called "Iron(III) oxide ".
The number in the parenthesis is "Valence" of the substance. Frankly, I don't know how to calculate such number. Can you explain to me, with this example, how come FeOFeO has valence 22 and the other one has valence 33?
The only thing I know how to do is calculate the electron configurations of each element.
For Iron, it is 1s22s22p63s23p64s23d61s22s22p63s23p64s23d6.
For Oxygen, it is 1s22s22p41s22s22p4.
I am told that based on the electron configuration you can get the valence of each element. And then, you can calculate the valence of FeOFeO and Fe2O3FeX2OX3.