 Okay, so let's try this one, just to emphasize the mole concept, right? So just looking at the periodic table, how much, how many grams does one mole of each of these things weigh? So if you look at the periodic table, NA, of course, is sodium. So look at the mass number of sodium, or the atomic mass of sodium. And you'll see that it's 22.9 Dalton. So remember our conversion factor that we just learned, right? So that's going to be per mole of sodium. It's going to be 22.99 grams of sodium per mole of sodium. What about calcium? What's that going to weigh in grams per mole? So it's going to weigh, well, its atomic weight is 40.08. So it's going to weigh 40.08 grams for every one mole of calcium. And then of course, sulfur, hopefully you're getting this by now. It'll just be, and this is per mole, 22.92 times 10 to the 23rd is 32.07 grams of sulfur. Then you must have the same number of grams as one atom weighs in on the periodic table, or the half that you see on the periodic table. One mole always contains 6.022 times 10 to the 23rd of anything.