# Chem

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Based on the number of atoms per unit cell and the mass of the atom, the mass of the unit cell can be calculated. The density of the unit cell and the material as a whole can be determined from the mass and the volume of the unit cell as.

D= M/V

The usual units of density are grams per cubic centimeter or .
Part A
Nickel, , has a face-centered cubic structure (Part A figure) with an edge length of 352 . What is the density of this metal? Use the periodic table as needed.

• Chem -

I need to know two things.
1. 352 what? meters, cm, pm?
2. What do you know about this problem? How much can you do and what don't you understand.

• Chem -

its pm

i guess we have to multipy by 10^-12

thn i don't knw abt mass

d=m/v
since i don't even knw the units too hw to cont

• Chem -

density = mass/volume.
First, calculate volume.
You know the edge length is 352 pm. Convert that to cm (since the problem wants the density in g/cc), then length^3 = volume (in cubic centimeters).
Now for mass.
A face centered cubic unit cell contains 4 particles so the mass of the unit cell contents is the mass of the Ni atom.
4*atomic mass Ni/6.022 x 10^23 = ?? grams of one unit cell.
Density, then, is ??grams/volume in cc.
Post your work if you get stuck.

• Chem -

In this case, the answer is 8.94 g/cm^3