Static Electricity - Understanding More About the Charge Imbalance and Balancing Process

Discussion in 'Physics' started by turkey3_scratch, Apr 18, 2016.

  1. turkey3_scratch

    Thread Starter New Member

    Apr 15, 2016
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    I understand the basic gist of static electricity. Two dissimilar insulators come into contact, the chemical properties cause one insulator to "steal" some charge from another insulator. This causes one insulator to have an excess of protons, and the other an excess of electrons, and a very strong electric field. Now here is where my confusion comes into play.

    In this instance, there is a major charge imbalance. Let's say Insulator A stole some charge (let's say electrons) from Insulator B. This causes Insulator A to be negatively charged and Insulator B to be positively charged, as shown in the dumbed-down image below.
    upload_2016-4-18_20-24-48.png
    After that separation, here's what I don't understand: If the electrons want to balance out, why doesn't one excess electron in Insulator A go over to Insulator B then? I understand that in real life it's usually upon a conductor that Insulator A would discharge one charge, but I don't understand why that charge wouldn't just jump back over to Insulator B, since it does want to balance out.

    Also, my second question. What determines what types of objects Insulator A will be able to discharge excess charge to, or "zap"? As for Insulator B, which has an excess of protons, what type of objects will discharge an electron to it? What's the difference henceforth in the results of these two insulators - one with an excess of protons, and one with an excess of electrons - coming in contact with different types of materials?
     
  2. nsaspook

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    Aug 27, 2009
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    For normal materials in a room environment it's the excess or deficit of electrons we normally consider in charge separation. The single electron can't just jump across empty space without the expenditure of energy to separate/accelerate one electron from the number of electrons near it in objects of macro size drude. Even if the total electrical potential between A & B is large the potentials between electron A1 and the universe in reference to it's position in space is usually much smaller due to the potential gradient between electron A1 and the rest of the electrons in the mass.

    http://www.ekasuga.co.jp/en/product/190/000310.shtml
     
  3. BR-549

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    Sep 22, 2013
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    I have never heard of that proposed setup for static charge worded that way. Two dissimilar insulators.

    I was taught that one object needed a low affinity for free electrons and the other object with at least some affinity for free electrons. Whatever.

    The energy needed for the charge transfer was supplied by the contact force. Friction.

    The objects retain there charge because of quick separation and the insulating properties of dry air.

    A negative charged object will discharge and neutralize when it contacts an object that can readily accept free electrons.

    A positive charged object will discharge and neutralize when it contacts an object that can readily donate free electrons.

    Earth ground can do both.
     
  4. turkey3_scratch

    Thread Starter New Member

    Apr 15, 2016
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    Thank you for your responses. A few things:

    1) If a positively charged object gains electrons in order to neutralize, it wouldn't be discharging, it'd be re-charging. At least in my mind that terminology makes more sense. The actual electron doner would be discharging to neutralize itself. But since the positively charged object gains charge, isn't discharge sort of backwards terminology?

    2) If a positively charged object is neutralized when it contacts an object that can readily donate free electrons, it doesn't make sense to me why Insulator A then can't donate a free electron to insulator B. Let me explain it better. Go back to the image I have above. Let's say after the separation process, after Insulator B gives an electron to Insulator A, let's say we make those two insulators come into contact again. In this case, Insulator A is an object that can readily donate an electron, and Insulator B is one that can readily gain an electron, so why would the electron not transfer back over to Insulator B upon this reunited contact?
     
  5. Peflomac

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    Apr 7, 2016
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    We need to agree on the basics: what is a charged particle and how charged particles interact in an atom.
    Unless we solve the fundamentals, everybody will give their own opinion and you will get confused more.
     
  6. nsaspook

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    An electric discharge is the release and transmission of electricity in an applied electric field through a medium.
     
  7. turkey3_scratch

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    Apr 15, 2016
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    Electricity is not released, charge is released. Electricity is just a fundamental term with contradictory meanings. Electricity is not the same as electric charge. If you look up the definition of electricity, it varies from book to book, dictionary to dictionary. The only conclusion about the word "electricity" is that electricity does not exist.

    It is the charge that moves. It is the charge that flows. It is the charge that is discharged. Charge and fields are basically the only two things that exist in this universe.

    Also, William Beaty is my primary source of knowledge. If you read the article http://amasci.com/miscon/whatis.html he comes to the conclusion that electricity does not exist. So how can you possibly say electricity is discharged after you link an article saying electricity does not exist? I have read that article multiple times in the past, I'm assuming you probably have not... ;)
     
    Last edited: Apr 19, 2016
  8. turkey3_scratch

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    Apr 15, 2016
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    A single charge I would define as an electron or a proton. A charged entity such as an ion is made up of charge and also has a charge of its own. An atom is made up of charge but does not have a charge.

    Yes, you are right, we need to define this stuff clearly because the words "electricity" and "charge" have so many different meanings.
     
  9. nsaspook

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    Why do you think I put the link in my answer? Because I know that if I used electricity in the way you used the word 'static electricity' in your OP we eventually would be at this point of asking, what is Electricity?

    Yes, I've read most of his web pages ages ago and agree with most with the notable exception of the Tesla fanboy stuff. :)
    https://www.physicsforums.com/threads/what-is-voltage.566192/page-2#post-3709247
     
    Last edited: Apr 19, 2016
  10. turkey3_scratch

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    Apr 15, 2016
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    The way I think of it is that "static electricity" is an appropriate term because it is the study of this charge imbalance, but just plain-old "electricity" alone does not make sense.

    But I still don't understand why you said it's a discharge of "electricity" if both of us agree "electricity" does not really exist. Are you trying to play some funky reverse psychology on me o_O

    Edit: After more thought, I understand your sarcasm. But fortunately I am clear of all those misconceptions! My matter here deals with charge. :)
     
  11. WBahn

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    Mar 31, 2012
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    You initial description was pretty much on the mark.

    When two dissimilar insulators are placed in contact (no rubbing or "friction" is needed, but it does amplify the effect since the rubbing results in the materials making and breaking contact many times) one material has a greater affinity for electrons than the other such that, when the materials are separated, electrons are transferred leaving one with a net positive charge and one with a net negative charge. By convention, both objects are said to be "charged" (note that the word "charge" is neutral (no pun intended) on the polarity of the charge -- it can be positively charged or it can be negatively charged. Thus, the term "discharge" generally means returning from a charged state to an uncharged (or discharged) state, again without respect to the polarity of the net charge involved.

    Once separated, the object that has a net negative charge (excess electrons) is a bit schizophrenic -- on the one hand it wants to eject the excess electrons as they repel each other. This is manifested by the fact that the net negative charge creates a net electric field that exerts a force on all of the electrons trying to pull them away from the material. But, at the same time, the material also has that affinity for electrons (usually because they complete outer shells in some of the atoms) and so wants to hang on to them. The affinity wins unless the electric field gets so strong that it is able to overcome the affinity and rip electrons off of the material. That is what happens as you move the charged object close to another object -- the closer they get the stronger the electric field gets (because the voltage between the two is constant which means that the rate at which the voltage changes has to increase as the distance gets less -- and the rate of voltage change IS the electric field). Once the field gets strong enough, electrons are ripped off and jump to the other material, generally ionizing the air between them which makes it much easier for further electrons to travel across the gap. This continues until the electric field drops to a point that can no longer sustain the flow of charge. At that point the original object is probably still somewhat negative charged, but much less so.

    A similar description applies to the positively charged material, except that it isn't schizophrenic -- it merely wants electrons to come to it; but that can only happen when the electric field between it and some other object is high enough to rip electrons away from the other material.
     
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  12. nsaspook

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    The physics definition of electricity as expressed by Coulomb's law is perfectly valid for "Static electricity". The problem is not that "electricity" does not really exist, the problem is the common meaning is imprecise to the point of being meaningless when used to express all the properties and interactions in electrical science and electronic circuit theory.
     
  13. turkey3_scratch

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    Apr 15, 2016
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    WBahn, thank you so much for the explanation. It makes 100% sense now.
     
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