8. Iron reacts with element X to form the compounds FeX and Fe3X2. When copper reacts with element X, the expected compound(s) should be A. CuX and Cu3X2. B. Cu2X and Cu6X. C. Cu3X only. D. CuX2 only. E. Cu3X and Cu3X2. ANSWRE IS E Iron forms the +3 or the +2 ion: Fe3+ (ferric) and Fe2+ (ferrous). The fact that it reacts with X to form FeX and Fe3X2 suggests that X forms an anion with a 3 charge. X3 reacts with the ferric ion to form FeX, since both have a 3 charge, but reacts with the ferrous ion to form Fe3X2 to balance the charge. Copper usually forms either the +1 or the +2 ion. When the former reacts with X, then, there must be three Cu+ ions to balance the charge, resulting in Cu3X. When the latter reacts with X, it does so in the same way that the ferrous ion does, forming Cu3X2. makes sense but i still dont know how to calculate the charges for transition metals...how are we supp to know that copper has a plus 1 and plus 2 charge.....how do we not know if it only has one of those or multiple charges?