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Homework Help: Element Density of Period 2

  1. Oct 24, 2008 #1
    1. The problem statement, all variables and given/known data
    Which of the elements, from the second period, has the highest density in its standard state?

    2. Relevant equations
    Standard state is gas at 1 atm, concentration of 1 M for liquid, or pure substance at 25C and 1 atm.

    3. The attempt at a solution
    I thought that N, O, F, and Ne could be removed from possibilities because they are gases. Then I looked it up and found Boron had the largest density, but that was incorrect.
  2. jcsd
  3. Oct 24, 2008 #2


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    Staff Emeritus
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    What did you find for densities for all the solids in that period?
  4. Oct 24, 2008 #3
    I found:
    Li: .534 g/cm^3
    Be: 1.85 g/cm^3
    B: 2.34 g/cm^3
    C: 2.267 g/cm^3
    N: .00125 g/cm^3
    O: .00149 g/cm^3
    F: .001696 g/cm^3
    Ne: .0008999 g/cm^3
  5. Oct 25, 2008 #4


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    I would say boron in the standard state is the densest.

    There is a little catch here - diamond (which is a pure carbon) has much higher denisty, something like 3.5 g/mL. But diamonds are not thermodynamically stable - they convert to graphite. Conversion is so slow, that for all practical purposes diamonds are stable - but thermodynamically they are not. Thus they are not standard state of the carbon.
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