Okay, So for this question, they tell us the radius of platinum is 139 pickle meters, and they want us to calculate the edge linked of the units. So Andy density. So the first thing that we have to do is calculate how much? One atom of platinum ways. So, Adam, right? So are we going to do is take the molar mass of one mole of platinum, and that is 195 0.64 g. We take that. That's one more time, and we can use discovers in one mo. And when an ah is equal to six points 02 two times 10 20 23rd. Adams. Right. That's all the goggles number. So one mole of any ah element as you go to 6.22 times sensor, 23rd Adams. We plucked out into de caca. We get 3.239 times 10 30 22 g. So that's how much one platinum Adam ways so. But the thing is, there are four atoms present in the unit cell of platinum because they tell us that platinum crystallizes with the face centre cubic units. L so face centred cubic units. L means that at each corner of the Cube there are one platinum Adam. And then there are one platinum Adam on each face of the cube. So since there are eight on each corner of the Q and each corner each Adam on the corner is only 18 inside. That's one right. And there sits on the surface and each surface. Adam is half inside last three and three plus one export. So I'm gonna take this number and multiply it by four. And we get 1 to 9 56 1.2956 times, 10 times 10. Trudy Negative. 21. Right. So that is the mass of the unit. So, uh, now we can save this value for later. So for part A, they're telling us to calculate D ed joins, right? So they tell us to Your radius of platinum is 139 PICO meters. So we can just use this ah, formula Right here. Length is equal to two square root of two times that by our right. So choose gravel of two times and by our 139 pickle meters. But we have to convert this Ah pickle meters into, actually, uh, after we can keep it as a PICO meter. Right. We put that into the calculate. We get length as you go to 393 p computers. Careful, Part B. They want us to calculate density. So what we have to do now is, since they want the answer in grams per setting, there's Cube. Were the convert this PICO meters into centimeters. Right. Okay, so we have 393 pick a meters. The conversion is one centimeter is equal to one times 10 to the negative. 10. He commuters. All right, put that into the calculator and we get 3.93 times 10 to the negative eight centimeters. Now, what we're gonna do is find volume. So we have the length of each side and centimeters. So 3.93 times 10 to the negative. Eight centimeters. Right? Volume is this is the cube. All sides are insanely. So we just got a cute this after we cute that we should get 60.698 times 10 sooty negative, 24 centimeters cube. Okay, so they want the density and grams per centimeters cube. Right. So we have Centimeters Cube, and we also have grams right here. So all we gotta do is take the two values and we just divide them. So, density does he go to mass? Divided by volume. So 129 points? Uh, not 129. It's 1.29 56 years, 1.2956 times, 10 to the negative. 21 over 60.698 times, 10 to the negative. 24 and we get 21 0.3 grams per centimeters cube.