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Homework Help: Distance between copper atoms in cubic crystal lattice

  1. Nov 10, 2008 #1
    1. The problem statement, all variables and given/known data
    The atomic mass number of copper is A = 64. Assume that atoms in solid copper form a cubic crystal lattice. To envision this, imagine that you place atoms at the centers of tiny sugar cubes, then stack the little sugar cubes to form a big cube. If you dissolve the sugar, the atoms left behind are in a cubic crystal lattice.

    2. Relevant equations

    3. The attempt at a solution
    This question is coming from the chapter dealing with Ideal-Gas laws. Also talks about moles and atomic mass numbers/atomic numbers, but I don't see how I can use the Ideal-gas laws (Boltzmann's constant) with a copper atom. I also don't see how knowing the atomic mass number even plays a roll in solving this problem... any help? I would honestly attempt the solution if I knew where to even start.
  2. jcsd
  3. Nov 11, 2008 #2
    wow.. i've never been so stressed over homework. I want to break something =( . Anyway.. I emailed my prof... his response " You can use the atomic mass number to determine the mass of any given volume of copper. Once you do that, you can compute the number of atoms in that volume and then go on just like the example in the book."

    So how do I use the atomic mass number which is the number of protons and number of neutrons in an atom to find a mass of any given volume of copper? Then I'm supposed to use "THAT" volume and go on like the example in the book that the ideal-law formulas are used? Are you kidding me? This makes NO sense. :( Is there any where else online I can read into this? Our book does a poor job of this...
  4. Nov 6, 2010 #3
    I don't want to bring up an old topic, but I can't figure this problem out either, I know the answer is .228 nm, and have been substituting all the basic equations for an hour and the best i can come up with is V = l^3 when the number density is 1.
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