 So this one says what is the root mean square velocity of a molecule in a sample of oxygen at 0 degrees Celsius? So if you recall the root mean square, so we'll do this the quick way. Okay, so the root mean square is mu average equals 3RT divided by the molar mass and you're going to square root that whole thing. Okay, remember to the half is the same as square root. Okay, so anyways, the way I like to do this is just put it all out in a line. So I'll show you what I'm talking about in a second. But let's write down what we've got. So the thing is is you have to recall that R is 8.314 joules per mole kelvin. So that's the ideal gas constant that's got to be given to you. But you got to remember which form of the gas constant you use in this particular problem you're going to be using 8.314. Temperature, of course, since this is in kelvin you've got to change your temperature to kelvin. So the temperature is in 0.0 Celsius. So we're going to add 273 to that to get 273.0 kelvin for our temperature. And molar mass, right? So molar mass, in this case, it's at oxygen. So oxygen, we have to recall, is a molecule O2. Okay, so it doesn't give us that information. So if we want to know, well, what's the molar mass of oxygen, we've got to look up the periodic table. So it's going to be 2 times 16.00 grams per mole. Okay, so is everybody okay with that stuff? Probably pretty good with that. Well, let's go about doing the problem now. And this is kind of where it's a little bit perry, especially for Jankem students, because you got to remember the joules conversion to kilograms, meters squared, seconds squared. Okay, so again, this is velocity average. So probably you want a good velocity set of units. Okay, so you would want to be thinking about that going into this. So anyways, this is the way I like it. So 8.314, per temperature, 273.0, you can see that's my cancel there. And then what I like to do is move that molar mass out to be 1 over m. So when we do that, of course, 1 over m is the same thing as looking at over. So in this case, it's going to be 1 mole, 32.0 grams. Is everybody okay with what I've done there? So that way I can cancel out the moles there. Recall that joules, joules is kilograms, meters squared, per second squared. So let's convert that because, well, well, we got to convert this to kilograms. Eventually. Okay, so we could do one or the other first if you'd like. Let's just, I guess, let's do the cancel there. Now we see, hopefully, you can see, well, I'm going to have to get rid of that kilogram, okay? So how do I do that? Well, one joule is one kilogram per meter squared, second squared. That's the way I like to do it. So you can see the units cancel out. And then when you do that, so hopefully you see, joules cancel there, kilograms cancel there. And what do we have left? Meter squared per second squared. Does everybody see that? Let's finish this. Right? Meter squared per second squared, but we're taking the square root of that. Is everybody okay with that? So when we take the square root of meter squared per second squared, what are we going to get? Meters per second, right? And is meters per second a good velocity set of units? Yes, okay. So hopefully everybody sees what I've done. Let's just get out of your calculator and start calculating. So three times k-point three, one, four, divided by thirty-two, I'm just wondering how I'm going to take the square root of that number. And I get, so this one is to, I guess this is the only units that we've used, right? So four. So four point, four sixty-one point three meters per second. So that's how fast the average oxygen molecule is going at zero degrees Celsius. Is everybody okay with that kind of a calculation? So again, I think the things in this one that you have to remember, well, there are some keynotes to remember. You've got to remember which gas constant you use. This is the only one you guys know so far, but we'll be getting into the ideal gas equation and they'll give you a new one. You have to remember that joules conversion, one joule equals one kilogram meter squared per second squared. And again, I like to do it like this, kind of show it out so you can see the meter squared per second squared. But if you can do it in your head, you don't have to show everything of course. Okay, any questions before I kill this one?