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Attraction of water droplet to my finger?

  1. May 20, 2006 #1
    After a rain, when there are tiny water droplets hanging down from places, I can put my dry finger near one of the droplets and if my finger is close enough to the droplet, it will jump onto my finger. Just like a metal jumping onto a magnet.

    What physical explanation could be given here? Is it simply the negative ends of all the water molecules in the droplet attracted to my positively induced finger?
     
  2. jcsd
  3. May 20, 2006 #2

    Hootenanny

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  4. May 20, 2006 #3
    i think you hit it, negative polarity on the oxygen end of water attracts to your positively charged finger.

    if you're finger was slightly wet though it would have been due partly to the polarity of the molecules and partly due to hydrogen bonding
     
  5. May 20, 2006 #4

    Hootenanny

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    This is indeed a good point, sweat contains not only the polar H2O water molecule, but also ionic compounds, which could contribute to the effect. If your finger is damp / sweaty you will have both cohesion and adhesion.

    ~H
     
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