Welcome. My name is Dr. Scott Melidio and in this short under 5 minute video we are going to take the tools that we have learned about in the previous videos of this series and use them to write the name and formula for a binary ionic compound with a transition metal. First we will go from the name to the formula. The main difference when working with a transition metal is that we have parentheses after the name of the transition metal that will tell us the charge and you may be asking yourself why. And the reason is that transition metals can have multiple charges to them and this is the way that we let people know what that charge is on the metal. We will start with the name iron 2 chloride. The 2 means that the iron has a positive 2 charge. As for the chlorine since it is a halogen it has a minus 1 charge. Based off of that information please pause the video and try to write the chemical formula yourself. Did you get FECL2? If not let's use our crossover method. Let's try another example. Nickel 3 oxide. Please pause the video to give yourself enough time. The answer to this is NI203. Again you can check your work by using the crossover method as shown. Before you can use the formula from a previous video. Remember the overall charge on an ionic compound must be zero. Now let's move on to going in the other direction with the following example, FEO. The tip here is always look at the anion to help figure out the charge on the transition metal. The reason to do this is that you should know the charge on the anion. In this case the charge on oxygen is minus 2. To determine the charge on our transition metal let us use the formula, the number of cation atoms times the charge of a cation plus the number of anion atoms times the charge of an anion equals zero. Using the given information we can set up the equation to look like this. One iron atom times x since we don't know the charge on the iron plus one oxygen times the charge of a single oxygen minus 2 must equal zero. Solving for x we have 1x plus negative 2 equals zero. Add 2 to both sides of the equation and we get x equals positive 2. This means that the charge on our iron is a positive 2. Then to write the name we would write it as iron 2 oxide. Don't forget your Roman numeral. Now it's your turn to try with this next example CUI2. Pause the video here to give yourself enough time to answer. Hopefully you got copper 2 iodide. If not let's use that formula again. One copper times x plus 2 iodide times negative 1 equals zero. We then get 1x plus negative 2 equals zero. Add 2 to both sides and we get x equals positive 2 and remember that x equals the charge on our copper. In the next video we will be covering ionic compounds that contain a polyatomic ion I hope this was helpful. Thank you for taking the time to watch this video.