It's also helpful at this point, to again, look at predicting. Ionic charges. Because the charge of the ion comes into play when we are naming these these things and particularly how they bind together, and how we represent them with a chemical formula. So if we have group 1A, they will have a plus one charge. Group 2A has a plus two charge. Group 3A will have a plus three charge. If we now look at group 7A, they have a -1 charge. Group 6A has a -2 charge. And group 5A has a -3 charge. In the group 6A there's an exception. And the exception here is peroxides, which will have a -1 charge. Notice that we skipped Group 4. The Group 4 complexes will generally form molecular compounds, which we'll discuss a little bit later, okay? In addition to the binary compound we need to look at nomenclature for transition metal complexes. So for transition metal or for transition metals we need to include extra information. And this quote unquote extra information is gonna be Roman Numerals. And this indicate the charge of the transition metal cation. So for example, there are two form of copper oxide. So copper oxide exists as CuO and Cu2O. The question is what is the difference between each of these? The oxide part or the oxygen is going to have a -2 charge. So the question is, what's the charge of each of these coppers in this particular complex. If it's CuO, that means the copper has to have a plus 2 charge or it's a plus 2 cation. For Cu2O, this is gonna have a plus 1 charge. So if we go to name each of these the first copper oxide is gonna be copper (II) oxide, and this Roman Numeral indicates the charge of the copper ion. Cu2o is gonna be copper (I) oxide so with these transition metals, they exist in varying oxidation states or with varying charges so we need to indicate that in parenthesis to distinguish between CUO and CU2O. Other examples if we were given the name and then went to our formula, if we were given iron, III bromide. Iron III bromide has a plus 3 charge on the iron, the bromide is in group 7A, so it's gonna have a -1 charge, so this has to be FeBr3 in order for the charges to cancel out. If we also looked at titanium four sulfide the titanium is gonna have a plus four charge the sulfur is in group 6A which gives us a minus two charge so that's gonna be TIS2, so this is the way, that if we have, binary complexes, where you have a cadine and an anine, this is how we would name each of them. And, this is the thought process we go through if we determine that we have an ionic compound.