 Okay, now let's try this one, I guess, write the following names of these transition metal polyatomic ions formulae as you can see just like the question implies. We have a series of transition metals and they're combined in ionic bond with these various polyatomic ions. So the real question is when we look at these complex, how do we start? The first thing you want to do is ask yourself, well, since all these are transition metals, we really don't know what the charge is because you don't have a regular charge scheme with these transition metal complexes or these transition metal ions. So what you can figure out, though, is if you've memorized all of your polyatomic ions, you realize what the charges of these polyatomic ions are and you've got to start there. So this compound has a nickel and a nitrate, so remember we have to do the polyatomic ion first, so nitrate is NO3 and we've got to remember that that's one minus. So if we've got two of them, the subscript says we have two of them, so let's just pull that two out in front, so that means we have two minus charges. So in order to balance two minus charges with only one nickel, that means that we've got to have nickel 2 plus. So 2 plus minus 2 equals 0, so the name of this compound is actually going to be nickel 2 nitrate. Let's go ahead and do this one now, again, cobalt is a transition metal, so we don't know what the normal oxidation state of this ion is, so we go over to our polyatomic ion here. We realize that the name of this ion is acetate, acetate is C2H3O2 and it's got actually minus charge on it, and if we look over here, it's got a subscript of two outside the parentheses, so we know that means that there's two of them. So we have an overall 2 minus charge, and when we're going to combine that with this cobalt, there's only one of them, so we know that the cobalt has to have an overall 2 plus charge to counterbalance that 2 minus charge like that, so it's going to be the same type of complex as the one before it, but we're of course going to name it differently, this is going to be cobalt acetate. Okay, so let's get into a more hairy one here, this iron phosphate thing. So of course PO4, we have to remember again is phosphate, so PO4, and what's the charge on a phosphate polyatom? Well that's negative 3, and again that's just something you've got to memorize, and we look back over at the formula unit, it's got a 2 outside the parentheses, so what does that mean? That means that there's two of them. So what we do now is take 2 and multiply that by 3, that gives us negative 6, okay? If we look over here, we've got 3 irons, okay? If we're going to try to get 6 out of that, it's just going to be 6 divided by 3, what is that equal? That equals 2, so we know that iron, 3 irons, are all going to have a plus 2 charge. So if we multiply 3 by 2, that equals 6 plus, right, and 2 by 3, that equals 6 minus. Those two balance out, give us 0, so this has got to be the right oxidation state. So what we have here is again, iron 2 phosphate, and finally, I guess I didn't make this problem very interesting because this is also going to have a plus 2 oxidation state, the zinc that is. But if we look at this, again we have to look first at the polyatomic ion. This polyatomic ion is cyanide. If we remember, cyanide has a minus charge, okay, with the 2 outside of the parentheses. Of course, it means there's two of them. Two times minus one is minus two, and since there's only one zinc atom, that means that the zinc has to counterbalance those two charges by itself, so that means it's going to be zinc 2 plus, and then if we go over here, we call this zinc 2.