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Thread: magnetic dipoles

  1. #1 magnetic dipoles 
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    A magnet has a N and a S pole to it, but if the electrons are always moving why are the N and S ends stationary instead of constantly changing/moving?
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    Electrons don't "orbit" like planets around the sun.


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    Because a magnetic field is established when the electrons move around each other, at the south pole there are more electrons and hence create a more negativley charged field and there are less electrons at the north pole. The electrons that are delocalised are able to move from atom to atom and usually the poles either have more or less electrons at either end permanetly either when electrons flow through the atoms, or whether they have stopped. The magnet, or rather dipoles have established an equilibrium and to now remove electrons from the negative pole would be too great and the north pole too small and hence the magnet basically says, "Oh I can't be bothered!" And things stay as they are even if no electrons are moving.

    In other words, the motion of electricity-the electrons moving through the metal causes electrons to be pushed away from being in balance, for example the electrons at the north pole have left and have ended up at the south pole, which leaves the dipoles detectable.
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    Quote Originally Posted by svwillmer
    Because a magnetic field is established when the electrons move around each other, at the south pole there are more electrons and hence create a more negativley charged field and there are less electrons at the north pole. The electrons that are delocalised are able to move from atom to atom and usually the poles either have more or less electrons at either end permanetly either when electrons flow through the atoms, or whether they have stopped. The magnet, or rather dipoles have established an equilibrium and to now remove electrons from the negative pole would be too great and the north pole too small and hence the magnet basically says, "Oh I can't be bothered!" And things stay as they are even if no electrons are moving.

    In other words, the motion of electricity-the electrons moving through the metal causes electrons to be pushed away from being in balance, for example the electrons at the north pole have left and have ended up at the south pole, which leaves the dipoles detectable.
    And why the electrons left the north pole?
    Why when I'll get closer permanent magnet to iron (or something), the molecules (or who knows what) line up and create magnet?
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    Quote Originally Posted by svwillmer
    Because a magnetic field is established when the electrons move around each other, at the south pole there are more electrons and hence create a more negativley charged field and there are less electrons at the north pole. The electrons that are delocalised are able to move from atom to atom and usually the poles either have more or less electrons at either end permanetly either when electrons flow through the atoms, or whether they have stopped. The magnet, or rather dipoles have established an equilibrium and to now remove electrons from the negative pole would be too great and the north pole too small and hence the magnet basically says, "Oh I can't be bothered!" And things stay as they are even if no electrons are moving.

    In other words, the motion of electricity-the electrons moving through the metal causes electrons to be pushed away from being in balance, for example the electrons at the north pole have left and have ended up at the south pole, which leaves the dipoles detectable.
    A lot of this is wrong, and a lot of it is incomprehensible. For one thing, you seem to be confusing magnetism an electric dipoles.

    Each individual electron is always producing a small magnetic field that points in a particular direction. In some materials every electron is paired with another electron whose magnetic field is pointing in the opposite direction - the result is that the magnetic fields of the two electrons cancel out and you have no net magnetism. This is called "diamagnetism".

    Sometimes there are unpaired electrons whose fields aren't canceled out by anything, but the magnetic fields are all pointing in random directions, so the material doesn't act like a magnet. This is called "paramagnetism".

    And sometimes there are unpaired electrons whose fields all point in the same direction, so that their magnetic fields cooperate and reinforce each other. That's "ferromagnetism". Ferromagnetic materials are what you think of as magnets.
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    Don't forget that electric dipoles and mangetic forces are the same and interlinked as electromagnetism, to furtur understand what I am saying read into special relativity to show what I mean.
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    End of the day anyway, all magnetism is electromagnetism at it's core.
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    Quote Originally Posted by svwillmer
    Don't forget that electric dipoles and mangetic forces are the same and interlinked as electromagnetism, to furtur understand what I am saying read into special relativity to show what I mean.
    An electric dipole is simply an electric field gradient across a molecule. That's not at all the same as a magnetic moment. There are plenty of molecules that have strong electric dipoles but are not magnetic, and plenty of magnetic materials that don't have dipoles. Oxygen gas is weakly magnetic, but it has no electric dipole.

    In order to create electromagnetism you need moving electrons. In most magnetic materials (like the magnets that you stick to your refrigerator) the electrons aren't moving. Electromagnetism (what you get when you wind some wire around an iron nail and hook it up to a battery) is not the same as ferromagnetism (what causes magnets to stick to your refrigerator). Yeah, they're both magnetism, but the magnetism occurs for different reasons.
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    We know that same charges repel and opposite attract them selfs. So if the electrons have dipole magnetic momentum, how will they repel, if they get closer with their opposite poles of the dipoles? Thank you.
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    Quote Originally Posted by scientist91
    We know that same charges repel and opposite attract them selfs. So if the electrons have dipole magnetic momentum, how will they repel, if they get closer with their opposite poles of the dipoles? Thank you.
    The magnetic forces between electrons are usually much weaker than the repulsive electric forces, so they aren't usually going to get very close together even though their magnetic fields might be trying to attract them.
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    Quote Originally Posted by Scifor Refugee
    Quote Originally Posted by scientist91
    We know that same charges repel and opposite attract them selfs. So if the electrons have dipole magnetic momentum, how will they repel, if they get closer with their opposite poles of the dipoles? Thank you.
    The magnetic forces between electrons are usually much weaker than the repulsive electric forces, so they aren't usually going to get very close together even though their magnetic fields might be trying to attract them.
    If the electrons act like tiny dipoles, than, they should arrange them selfs to create one bigger magnet.
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    Quote Originally Posted by Scifor Refugee
    Quote Originally Posted by svwillmer
    Don't forget that electric dipoles and mangetic forces are the same and interlinked as electromagnetism, to furtur understand what I am saying read into special relativity to show what I mean.
    An electric dipole is simply an electric field gradient across a molecule. That's not at all the same as a magnetic moment. There are plenty of molecules that have strong electric dipoles but are not magnetic, and plenty of magnetic materials that don't have dipoles. Oxygen gas is weakly magnetic, but it has no electric dipole.

    In order to create electromagnetism you need moving electrons. In most magnetic materials (like the magnets that you stick to your refrigerator) the electrons aren't moving. Electromagnetism (what you get when you wind some wire around an iron nail and hook it up to a battery) is not the same as ferromagnetism (what causes magnets to stick to your refrigerator). Yeah, they're both magnetism, but the magnetism occurs for different reasons.
    How is possible that the electrons aren't moving? Please give me example where there are strong electric dipoles but they are not magnetic! As you said maybe the electrons are opposite moving so the magnetic field is canceling. If we think deeply, the electric field is same with the magnetic field.
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    Quote Originally Posted by scientist91
    If the electrons act like tiny dipoles, than, they should arrange them selfs to create one bigger magnet.
    Yes, and that's exactly what happens in magnetic materials!

    But remember, like I said earlier, in many materials (diamagnetic materials) every electron ends up paired with another electron that's pointing in the opposite direction, so there isn't a net magnetic field. In every other material, the electrons generally will arrange themselves to create a big magnet at sufficiently low temperatures. If the material is too warm, the heat energy in the material will randomly break up the cooperative ordering of the electron's dipoles, and they will all end up pointing in a random direction. But if you decrease the heat energy enough (in other words, if you cool it down) eventually you will hit a temperature called the "critical temperature" at which the electrons will begin to order. The critical temperature varies from one material to another. There are many things that have unpaired electrons but that don't actually become magnetic until you cool them down to very low temperatures. Some things have high critical temperatures, which allows them to be magnetic at room temperature.
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    Quote Originally Posted by scientist91
    How is possible that the electrons aren't moving?
    Because they aren't moving. They are just sitting stationary in their orbitals...I'm not really sure what else to say.
    Please give me example where there are strong electric dipoles but they are not magnetic!
    Water is diamagnetic, even though it has very strong dipoles between the oxygen and hydrogen.
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    Quote Originally Posted by Scifor Refugee
    Quote Originally Posted by scientist91
    How is possible that the electrons aren't moving?
    Because they aren't moving. They are just sitting stationary in their orbitals...I'm not really sure what else to say.
    Please give me example where there are strong electric dipoles but they are not magnetic!
    Water is diamagnetic, even though it has very strong dipoles between the oxygen and hydrogen.
    So, probably the electrons are moving in opposite directions in the water atom, so it do have strong electric dipoles but not magnetic field. Am I right?
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    Quote Originally Posted by Scifor Refugee
    Quote Originally Posted by scientist91
    We know that same charges repel and opposite attract them selfs. So if the electrons have dipole magnetic momentum, how will they repel, if they get closer with their opposite poles of the dipoles? Thank you.
    The magnetic forces between electrons are usually much weaker than the repulsive electric forces, so they aren't usually going to get very close together even though their magnetic fields might be trying to attract them.
    If the repulsive electric forces are stronger than the magnetic forces, by analogy, when I get no matter how close or how far two electrons they'll repel them selfs, and not line up.
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    Quote Originally Posted by scientist91
    So, probably the electrons are moving in opposite directions in the water atom, so it do have strong electric dipoles but not magnetic field. Am I right?
    The electrons in a water molecule are not moving. You can think of each electron like a tiny bar magnet. It doesn't have to move to create a magnetic field; it has an inherent magnetic field, even when it's just sitting in one place doing nothing. Water is diamagnetic because each electron is paired with another electron that's oriented in the opposite direction. Because they are paired, their magnetic fields cancel each other out.

    The electric dipole simply has to do with how the charge is distributed around the atom - it doesn't have anything to do with magnetism.
    If the repulsive electric forces are stronger than the magnetic forces, by analogy, when I get no matter how close or how far two electrons they'll repel them selfs, and not line up.
    The electrons all repel each other, but they're also all attracted to the positively-charged nucleus. That makes them hang around each other (so they can be near the nucleus), even though they want to repel.
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    In water molecules, you have 1 oxygen and 2 hydrogen atoms, hence H2O
    The hydrogen atoms are in a covalent bond, when the atoms share electrons. Since the oxygen atom has 2 electrons missing to fill the outer shell full, and hydrogen needs 1 electron to fill its outer shell. So the two electrons from the hydrogens go into the oxygen atom and around the hydrogen too. This is called a hydrogen bond and is the strongest intermolecular bond i know of. It's because when the electrons are absent in one area, it causes a dipole which acts like a magnet. Ask the other guy on this, he'll know more.
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    Quote Originally Posted by svwillmer
    In water molecules, you have 1 oxygen and 2 hydrogen atoms, hence H2O
    The hydrogen atoms are in a covalent bond, when the atoms share electrons. Since the oxygen atom has 2 electrons missing to fill the outer shell full, and hydrogen needs 1 electron to fill its outer shell. So the two electrons from the hydrogens go into the oxygen atom and around the hydrogen too.
    Okay, that's true...
    This is called a hydrogen bond and is the strongest intermolecular bond i know of.
    Well, a hydrogen bond is when one water molecule sticks to another water molecule because of electric forces...but I guess that might be what you meant.
    It's because when the electrons are absent in one area, it causes a dipole which acts like a magnet. Ask the other guy on this, he'll know more.
    No. An electric dipole is not the same as a magnetic dipole. An electric dipole only has to do with how the electrons are arranged around a molecule. It doesn't have anything to do with magnetism. Magnetism has to do with how the magnetic fields of the electrons are oriented relative to each other. The two are not the same.

    I'll repeat: There are plent of diamagnetic things (like water) that have strong dipoles but are not magnetic, and plenty of things without dipoles (like diatomic oxygen gas) that are magnetic.
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    How will two dipole tiny magnets (electrons) with opposite poles (lets say N and S) will attract them selfs, when they repel them selfs?
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    So electric and magnetic dipoles are commonly seperate? I didn't know. So electromagnetism is only when a moving electric current creates a magnetic field and vice versa?
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    Quote Originally Posted by scientist91
    How will two dipole tiny magnets (electrons) with opposite poles (lets say N and S) will attract them selfs, when they repel them selfs?
    There is one force (the magnetic force) that's attracting them, and another force (the electrostatic force) that's repelling then. The electric force is generally much stronger than the magnetic force, so overall they repel. But they can still align themselves so that their poles face the same direction even though they are repelling. Like I said, they're forced to hang around each other because they're all attracted to the positive nucleus.
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    Quote Originally Posted by Scifor Refugee
    Quote Originally Posted by scientist91
    How will two dipole tiny magnets (electrons) with opposite poles (lets say N and S) will attract them selfs, when they repel them selfs?
    There is one force (the magnetic force) that's attracting them, and another force (the electrostatic force) that's repelling then. The electric force is generally much stronger than the magnetic force, so overall they repel. But they can still align themselves so that their poles face the same direction even though they are repelling. Like I said, they're forced to hang around each other because they're all attracted to the positive nucleus.
    And why moving charge produces magnetic field?
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    Quote Originally Posted by scientist91
    And why moving charge produces magnetic field?
    I don’t really know…you would have to ask a physicist.
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    hahahahah realy hahahahahahahaha
    Solomon Grundy
    In 1944, this creature rose from the swamp, with tremendous strength and some dormant memories that for example allowed him to speak English, but not knowing what he was, and not remembering Cyrus Gold or his fate. Wandering throughout the swamp, he encountered two escaped criminals, killed them, and took their clothes. When they asked him his name, he simply muttered that he had been born on Monday. Reminded of an old nursery rhyme about a man born on Monday, the thugs named the creature "Solomon Grundy".
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