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Homework Help: Calculating the diameter of a polonium atom

  1. Jul 5, 2010 #1
    1. The problem statement, all variables and given/known data
    Polonium has a simple cubic structure at room temperature. Given that the mass density of solid [tex]^{209}_{84}[/tex]Po is 9.2gcm^-3 , calculate the diameter.

    3. The attempt at a solution

    Volume = mass/density = 209/ 9.2 = 22.7 cm^3

    1 mole = 6.02 x10^23 mol^-1

    22.7 / 6.02x10^23 = 3.77 x10^-23 cm

    volume = 4/3 (pi) r^3

    So diameter is 4.16x10^-10 m ?

    Is this correct? I have no answers to refer to. Thank you.
  2. jcsd
  3. Jul 5, 2010 #2
    It looks absolutely correct to me.
    Other than the third step where you (accidentally?) put "cm" instead of "cm^3"
    But the answer I think is right.

    Also, angstroms would be a more convenient unit, as it is 10^(-10)m.
    so the answer could be:
    4.16 angstroms
  4. Jul 5, 2010 #3
    How would you stack balls so that they fill the whole space?
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