 So if you recall, density, z, molar mass times s cubed and a, Apagodra's number. So Apagodra's number is 0.02 times 10 to the 23rd per mole. z we've got, s we've got, and the molar mass of silver. How do we find that? We look up at the periodic table. We'll say 107.9. Is everybody OK with those things? Remember, this will be given. So honestly, you don't need to know the radius to do this problem, even though that's usually the problem that's given right before. So z for face centered is 4. So if you recall, when we do the conversion to 107 times 10 to the negative 8 centimeters, that's something you want to get into your head just to do that. And remember, I think I've done that conversion on a couple of these days. So centimeters or grams per centimeter. Now let's just check it out. So do that. Big digs, 10.6 grams of the face centered packing silver. Hey, did anybody have any questions on this one? Good job, guys.