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Homework Help: How to calculate the density of an iron nucleus

  1. Oct 4, 2009 #1
    1. The problem statement, all variables and given/known data

    An iron nucleus has a radius of 5.4x10^-15 and a mass of 9.3x10^-26 what is its mass per unit volume in kg/m^3

    2. Relevant equations

    Area of a sphere = 4/3(pi)r^3
    Density= M/V

    3. The attempt at a solution

    i basically plugged everything into the equations so calculated the volume and put it into the density equation but my answer is far to high i think

    im getting 1.4x10^17 kgm^-3

    just need some clarification on how to complete it or if im right or not
  2. jcsd
  3. Oct 4, 2009 #2
    your calculation is Ok.
    the size of an iron atom is 1.4*10^-10 m. This means that the radius of the core is about 26000 times smaller, and the volume is 26000^3 smaller, so about 1.7*10^13 times smaller.
    If you compress iron until all the empty space between the cores is filled in it will become 1.7*10^13 times more dense.
  4. Oct 4, 2009 #3
    ok thanks just wanted to check =]
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