[kir]

Hi, I am stuck on the following: Copper Metal has a fcc unit cell with and edge length of 362pm. What is the Density of the metal in g/cm3?
My professor has given the answer: D=8.99 g/cm3 and I have 8.89 x10^-6g/cm3.
I can't determine where I went wrong:
FCC= 4 atoms per unit cell
362pm(1m/1*10^12pm)(100cm/1m)3= 4.74*10^-29cm3

D= 4(63.5g/mol/6.022*10^23mol) over 4.74*10^-29cm3

Thanks for the help.

[Borek]

362pm(1m/1*10^12pm)(100cm/1m)3= 4.74*10^-29cm3

Check your math.

[kir]

Thanks, I went over and over the problem but still kept missing it!

[Wald_ron]

Thanks, I went over and over the problem but still kept missing it!

1*10² * 1*10^-12 * 1*10² = 1*10^-8

[fledarmus]

Thanks, I went over and over the problem but still kept missing it!

1*10² * 1*10^-12 * 1*10² = 1*10^-8

Wald_ron, you left out all the cubes

[fledarmus]

Thanks, I went over and over the problem but still kept missing it!

It looks like you may have missed a cube in there as well - I get the same number but a different exponent than you got when I run it through my calculater

[Borek]

It looks like you may have missed a cube in there as well - I get the same number but a different exponent than you got when I run it through my calculater

The cube is there, just written in a way that doesn't make much sense:

362pm(1m/1*10^12pm)(100cm/1m)3= 4.74*10^-29cm3

[fledarmus]

It looks like you may have missed a cube in there as well - I get the same number but a different exponent than you got when I run it through my calculater

The cube is there, just written in a way that doesn't make much sense:

362pm(1m/1*10^12pm)(100cm/1m)3= 4.74*10^-29cm3

No, I meant when you punched it into the calculater. I realize you wrote it into the equation, but you seem to be off by a factor of 100³ with your answer.

[kir]

Sorry I wasn't clear, after the first helpful response this morning, I realized my error. I meant that before posting I went over and over the problem and couldn't figure out where I went wrong!
Thanks