now, when asked to determine the oxidation number of a non listed element within a compound, we're gonna follow the next four steps. Now, remember, we've gone over the specific oxidation number rules for certain elements. This applies to elements that are not found within that list. So step one, you're gonna treat the non listed element as X You're gonna right. You're gonna use the list to write the known oxidation number off other elements within that compound. For example, if you see oxygen is in that compound and it's not a peroxide or super oxide, we know it's oxidation. Number would therefore be minus two. Step three. If Element has a sub script, then remember to distribute it and then step four. Add up the oxidation numbers, create an equation and make it equal to the charge off the compound. So these are the rules that we're going to employ when looking for non listed elements within a compound, and we'll see how how we use utilize these four steps to get to our oxidation number for that particular element. Now that we've gone over them, click on the next video and let's take a look at an example question