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Thread: Will any mixture eventually settle out?

  1. #1 Will any mixture eventually settle out? 
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    I theorize that any mixture (not chemical compound) left undisturbed for long enough, would eventually separate itself into distinct layers of elements as long as they are acted upon by a constant one-directional force. This includes our atmosphere. If theoretically we could contain air (our atmosphere) and keep it undisturbed for long enough (except for gravity), that the Nitrogen, Oxygen, Carbon Dioxide and other elements present in our atmosphere would separate out, creating distinct layers.
    Is this true?
    Or might there be other forces holding the components of our atmosphere together?


    djfranzel
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  3. #2  
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    NO


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  4. #3  
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    NO, the components are not HELD together , actually they are constantly being mixed by thermal energy.
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  5. #4 Re: Will any mixture eventually settle out? 
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    Quote Originally Posted by djfranzel
    Or might there be other forces holding the components of our atmosphere together?
    For many mixtures the random thermal motion of the mixture will be enough to ensure that it never "settles." I suspect that our atmosphere is such a mixture, although I couldn't tell you for sure.
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  6. #5 Re: Will any mixture eventually settle out? 
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    Quote Originally Posted by djfranzel
    I theorize that any mixture (not chemical compound) left undisturbed for long enough, would eventually separate itself into distinct layers of elements as long as they are acted upon by a constant one-directional force. This includes our atmosphere. If theoretically we could contain air (our atmosphere) and keep it undisturbed for long enough (except for gravity), that the Nitrogen, Oxygen, Carbon Dioxide and other elements present in our atmosphere would separate out, creating distinct layers.
    Is this true?
    Or might there be other forces holding the components of our atmosphere together?
    The energy gained by having the heavier elements closer to earth would have to outweigh the loss of entropy. Maybe if gravity was stronger, or if the gases had a much bigger difference in density that might be true, but I don't think it would happen with our atmosphere on earth.
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  7. #6 Re: Will any mixture eventually settle out? 
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    Quote Originally Posted by djfranzel
    I theorize that any mixture (not chemical compound) left undisturbed for long enough, would eventually separate itself into distinct layers of elements as long as they are acted upon by a constant one-directional force. This includes our atmosphere. If theoretically we could contain air (our atmosphere) and keep it undisturbed for long enough (except for gravity), that the Nitrogen, Oxygen, Carbon Dioxide and other elements present in our atmosphere would separate out, creating distinct layers.
    Is this true?
    Or might there be other forces holding the components of our atmosphere together?
    You're speaking of differentiation, on a much smaller scale.
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  8. #7  
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    I do realized that the thermal energy would be constantly changing things, but, if the thermal energy remained entirely constant, then might the elements separate out?
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  9. #8  
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    The elements and compounds in the atmosphere do separate out in one sense. There is almost no hydrogen because it can escape Earth's gravity, while the heavier gases cannot. Ditto helium.

    Furthermore, there is lots of water vapor in the troposphere and very little water vapor in the stratosphere, while oxygen and CO2 are in the same proportions. Offhand I don't know why this is.
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