In this question we have a reaction between Potassium phosphate (K3PO4) and Iron(II) nitrate (Fe(NO3)2), now first we need to find what is the complete reaction and also balance it, and we will do that by matching the numbers of elements on both reactants and products side:
A) 2 K3PO4 (aq) + 3 Fe(NO3)2 (aq) -> Fe3(PO4)2 (s) + 6KNO3 (aq)
Now the physical states will be very important in the following questions, because solids will not dissociate in water, therefore there is no need to account for its charge, we only do that with aqueous compounds that will dissociate in water releasing ions.
B) To form the complete ionic equation we basically need to find what is the charge for each ion and form the equation with this information:
6 K^+ (aq) + 2 PO4^3- (aq) + 3 Fe^2+ (aq) + 6 NO3^- (aq) -> Fe3(PO4)2 (s) +
6 K^+ (aq) + 6 NO3^-
This is the complete ionic equation with all the charges of the ions
C) Spectator ions are ions that will not change when it undergoes the reaction, remaining in the same state and the same charge, in this question we have potassium ion (6 K^+) and nitrate ion (6 NO3^-) being the same, not forming any compound and having the same charge
D) The net ionic equation will be the part of the equation in which there is no spectator ions, the "functional" part of the reaction
2 PO4^3- (aq) + 3 Fe2+ (aq) -> Fe3(PO4)2 (s)
This is the net equation