 Okay, so let's try this first one on practice exam A. It says the distance between carbon atoms and ethylene is 134 picometers. Which of the following expressed the distance in meters? So let's just figure it out. So how do we do this? So 134 picometers. Does anybody know the conversion factor between meters and picometers? Something that we're supposed to know off the top of our heads. Remember the metric to metric conversions. So there's enough of us in here that you can help me. What is that conversion? It's 10 to the negative 12. 10 to the negative 12. Yeah, so for every 1 times 10 to the negative 12 meters, that equals 1 picometer. Or you can say for every 1 meter, that equals 1 times 10 to the 12 picometers. Like that. So you can use either one of those conversion factors that you want. Alright, so what do we do? We're going to cancel out picometers and get meters. So we're going to put picometers on the bottom. So 1 times 10 to the 12, 1 meter, cancel, cancel. And when we do that, we're just going to move that 2 and then to the negative 10. So 1.34 times 10 to the negative 10. So that's how you do that. So are there any questions on that particular question? Pretty straightforward. I think the hardest thing for us at this day is to recall these conversion factors. Okay? So are there any questions on that one or can I kill it?