1. Iron (Chemical symbol Fe) has 26 protons. Thus neutral iron has 26 electrons, the IV ionization state corresponds to the loss of 3 of these (Fe I is neutral iron), so Fe IV has a charge of +3 and a total of 23 electrons.

2. Oxygen (chemical symbol O) has 8 protons. Thus neutral Oxygen has 8 electrons and the highest possible ionization state is O IX, corresponding to the loss of all 8 electrons (O I is neutral Oxygen, O II is the +1 ionization state, and so on).