now remember that we can utilize mass ratios and proportions to determine if different samples represent the same compound. In addition to this, you can determine the unknown amount of an element if you know the mass ratio and the mass of the other element. Now again, we're utilizing proportions in order to do this. If we take a look at this example question, it says a compound contains Onley, calcium and Florrie Ah sample of the compound is determined to contain g of calcium at 1.90 g of flooring according to the law of definite proportions. How much calcium should another sample of this compound contain if it possesses 2.85 grands of foreign? So remember, following the law of definite proportions, we know mass ratio a must equal mass ratio be for mass ratio. A. We know that we have 2 g of calcium toe, 1.90 g of flooring. We place the larger mass on top and the smaller mass on the bottom, and we know that if they represent the same compound, then this ratio has to equal. Here we have 2.85 g of flooring and we don't know the grams of calcium. That's what we're looking for. We just established proportions, and that's gonna help us find out what X is. So remember, Cross multiply 1.90 times X and then we're gonna multiply two times 2.85 So when we do that, we're going to get 1.90 X equals 5.70 Divide both sides now by 1.90 in orderto isolate X. And when we do that, we're going to see that X equals 3. g, and that would be grams of calcium. So setting up these proportions helps us to realize that the answer would have to be options. See? So just remember, we can utilize our ratios in order to determine if our samples represent the same compound or in this instance to actually determine the mass of one of the element components. So just utilize these steps and you'll be able to figure out anything dealing with law of definite proportions.