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Homework Help: Material science-Specification of composition

  1. Sep 20, 2005 #1
    Im given this problem:
    Ge forms a substitutional solid solution with Si. find the weight% of Ge, that must be added to Si to yield an alloy that contains 2.43x10^21 Ge atoms per cubic centimetr. The densities of pure Ge and Si are 5.32 and 2.33 g/cm^3, respectively.

    then I have a formula that says C1=(m1/m1+m2)*100% where C1 is the concentration in weight % of material 1 and m1 is the mass of material 1, and m2 is the mass of material 2. I use this formula, and i get 72% for Ge, but the correct answer is 11.7%. does anyone know what i am doing wrong?
  2. jcsd
  3. Sep 21, 2005 #2
    Is this problem from Materials Science and Engineering Intro by William D CallisteR?

    If it is then it's question # 4.22. Anyway try doing #4.20 first, or just simply use the equation thats given in # 4.20.
  4. Sep 21, 2005 #3
    it is that book, but it is in chapter 5, not chapter 4.
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