 Okay, so let's try this problem I just made up in my head. So if I have 6.42 milligrams of caffeine, how many atoms are in that 6.42 milligrams, okay? So what do I need to do? So this is milligrams of caffeine. Can anybody help me out? And trying to convert this in order to get the number of atoms in that amount of mass? So that's the first thing I need to do. Converted to grams, yes, very good. To grams first. Why do I have to do that? Why can't I do the molar mass first? Because the molar mass is in grams. Molar mass is in grams per mole, right? Yeah. So how many milligrams am I gonna put down here? 1,000 to one gram like that. Everybody okay with that one? I'm just gonna leave that caffeine part out so it'll be too long and we'll go off the end of the board. So now what are, so what units am I in now? Grams. Grams, right? So what do I need to convert to next because we're trying to get to atoms, right? Moles, right? So how do I convert from grams to moles? What's that called? Molar mass, very good. So what am I gonna put at the bottom, down here? Grams. And up here, moles. And it's gonna be one mole and we calculated the molar mass in the last problem. What was that molar mass that we said? 1.4.2. 1.4.2, correct. Everybody okay with that? Any questions on that? So are we in atoms yet? What units are we in? Moles. Moles, okay. So how do we go from moles to atoms? Yeah, we multiply by alpha-gadget's number so that means what's at the bottom here? Moles. Moles, how many? One. One. Very good. And up here? 6.022 times 10 to the 20th. Atoms. Love, is that atoms? No, not this one. This is molecules, right? This is molecules, okay? Almost tricked myself. So, can we, do you have a conversion factor between the number, so one molecule and the number of atoms? How many atoms are in this molecule? No, no. How many atoms? How do we figure that at 24? It's 24, right? So, eight plus two is 10, plus 10 is 20, plus four is 24, okay? So, watch out about those things, okay? So, you can ask that question, okay? How many atoms are in this molecule? So, how many atoms do we say are in this molecule? 24. 24, are we gonna put that at the top or at the bottom? Top. Top. 24 atoms per caffeine molecule. Cancel. Cancel. Everybody okay with that canceling there? Do we get the atoms yet? Yes. Yes. So, now it's just, put in your calculator, multiply it by 6.42 divided by 1,000. Divide that number by 194.2. Multiply that number by 6.022, 23. Then multiply that number finally by 24. And this is to how many sixes? Three. So, it's gonna be 4.78 times 10 to the 20th. So, remember, just it's a logical step-by-step process, okay? A logical step-by-step process. You know these conversion factors or you should be able to, you don't know them logically come up with them in your head like we did that last one. 24 molecule or 24 atoms through a molecule. Any questions before we kill it?