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Thread: help please..

  1. Sep 20th 2008, 01:43 PM #1
    RicLang
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    help please..

    pure gold can be made into extremley thin sheets called gold leaf. suppose that 50. kg of gold is made into gold leaf having an area of 3620 m^2. The density of gold is 19.3 g/cm^3

    a. how thick in micrometers is the gold leaf?
    b. a gold atom has a radius of 1.44E-10 m, how many atoms thick is the gold leaf?

    thanks in advance!

    Ric
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  2. Sep 20th 2008, 02:24 PM #2
    skeeter
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    volume = (mass)(density)

    volume = (area)(thickness)

    so ...

    (mass)(density) = (area)(thickness)

    solve for thickness.

    part 2 ...

    # of atoms = (thickness)/(diameter of a gold atom)

    remember that diameter = 2(radius)
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