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Please explain (1 Viewer)

lil tiger

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in electrical conductivity, i know electrons are allowed to flow. Say the electrons in a metal are electrons (A), and the electrons in the electrical current electrons (B). When the electron flows to the metal and out to another conducting surface, do the electron get electrons (A) flow out or do they replace electrons (B) in the metal and electrons (B) flow out?
 

Xayma

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When an electron field is generated, all free electrons move. They move at a speed of something like 10<sup>-4</sup> ms<sup>-1</sup>. What will happen is if B is the electrons from the power source, they will move in and replace Electrons A as they move forward. So the only change in numbers of electrons is at the power source, where more electrons are at the positive side then there were before.
 

lil tiger

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Does the flowing of electron change the neutral state of the conductor and the power source( if its possible)? I mean where are the electrons going?
 

Xayma

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It wont change the overall charge of anything. The amount of electrons leaving the conducting material is = to the number of electrons entering it, so it remains neutral (but has a magnetic field), the power source remain overall neutral but the positive and negative end become less positive and negative as electrons go from the negative to positive end. AC current is a bit different.
 
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noo, thats not it
metal conductors: are like an even lattice of ions, in a "sea" of delocalised electrons. ie like its just the neutrons stuck together, with electrons swimming all around. Each electron isnt associated with a particular neutron or anything, they have NO ATOMIC IDENTITY. The electrons are ALWAYS MOVING but in like random directions (no net movement) until u apply a a charge.

basically conduction is the net movement of electrons.
electrons arent coming in from somewhere
or going anywhere
theyre there already


so basically nothings being replaced.
 
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abdooooo!!!

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thats what Xayma said, i think, you misunderstood his post. im a expert at electron theory of electricity. :D

i would just like to point out that electricity is a flow of charged particles, ie protons, electrons... and not just electrons. but in common metals its 99.9% electrons because of its delocalised electrons. :D

the particles actually move very slowly, but some books claim that they move at the speed of light, but this not true. its the energy ie the potential difference induced force that moves at the speed of light.

so to answer the original question. just think the metal wire as a pipe filled with water already. when you pump water from one side to the other you have to create a potential difference in amount water in the 2 sides ie the end of the pipes. and after some time then you stop this by blocking the sides, there will still be the same amount of water in them pipe, except now they are not the same water as they were at the start. so yes they get replaced. but this electrons don't actually move very fast, its the speed at which the signal of the water movement is being sent that travel at the speed of light.

hey lil tiger, do you do chemistry? if you do then, i think what you were after is an electrolytic cell. its used in many different applications to change states of substances ie metals for industrial purposes by the use of external power source. you should just read text book... can't be bothered to explain everything. :)
 
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Xayma

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Originally posted by worlds greatest
metal conductors: are like an even lattice of ions, in a "sea" of delocalised electrons. ie like its just the neutrons stuck together, with electrons swimming all around.
Ok Ill just correct one thing. The delocised electrons are around neucleus' not just neutrons.

Actually I cant help it. In a DC current electrons enter and leave the conductor. That is how a battery becomes flat, all the excess electrons are moved from the negative end to the positive end, eliminating the potential difference between two substances.

In an AC current there is net movement of electrons, that is because they move one direction then turn around and move the other direction I think this was the situation you were describing.
 
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abdooooo!!!

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Originally posted by Xayma
Ok Ill just correct one thing. The delocised electrons are around neucleus' not just neutrons.
ok like i said before im a expert at this theory of electrons... so correction... its "delocalised" electrons. and they don't orbit the neucleus, but rather they orbit "ALL" the atoms/ions that is the whole metal in a random, but high speed movement. and only the electrons that still remain attached to the atom orbits around the neucleus (which contains the protons and neutrons); that is if you still believe the "model" of orbital energy.

so you people are all wrong...LOL.
 
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abdooooo!!!

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Originally posted by Xayma
Actually I cant help it. In a DC current electrons enter and leave the conductor. That is how a battery becomes flat, all the excess electrons are moved from the negative end to the positive end, eliminating the potential difference between two substances.
what the hell are you talking about here? battery? that has nothing to do with the original question... a better example should just be electrolytic cell that is used to purify copper or some other metal if you wanted to talk about change in state.

anyway i don't think thats what worlds greatest meant anyway. i think he/she just wanted to point out that the wire already contained electrons at the first place like my example with the pre-filled pipe. so yea stop arguing and listen to me. :D
 

Xayma

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I used a battery as an example as that is the most used source of DC electricity, where the electrons from the source replace the electrons in the conductor. In an AC current they dont.
 
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abdoo. youre a .... confident person
Originally posted by abdooooo!!!


so you people are all wrong...LOL.
nb
u said everything i said


haha its so stupid the person who started this thread isnt even reading it
 

abdooooo!!!

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when the hell did i turn confident... ahahaha... im damn scared to write anything in the hsc exam. hsc english markers they're everywhere... :mad:

i think you people just don't read each others' post properly... the person who started this thread already got too confused. :D
 
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everyone thinks their answer is right, otherwise they wouldnt give it
how do u know ur anwers are "righter" than others?
 

lil tiger

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I'm still here reading and getting a little confused
please clarify each point

1. are electron replaced or just moved around in the conductor once a current flow past? it is same for DC and AC?
2. i recall abdhoo saying something about the current is 99.9% electrons. What makes the tiny bit remaining?
3. is hole current the flow of protons (since they call it positive charge flow)?

these answers may have already been answered, if so excuse me
 

Xayma

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1. Electrons have a net movement in a DC current, if you have three electrons and four spaces ABCD. The electron in place A goes to B, B to C, C to D. Going from the negative end of a battery to a positive.

2. Ions

3. Hole current is used to explain conventional current. It doesnt actually exist, but they made conventional current flow from positive to negative before they learnt about electrons. Basically if you have a whole in a line of electrons and the electrons move from negative to positive, the hole moves from positive to negative, it doesnt really carry a current.
 

abdooooo!!!

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1. its just replaced in the metal like my water example if its a direct current. and in alternating current the electrons just moves back and force.

2. yeah other charged particles. because you have to realise there is no such a thing as 100%, its like when we say there is no air in outer space, this just means that it is in a such a small amount that its undetectable.

3. electricity is a flow of charged particles, it can be either protons or electrons. but the thing is, protons are not present most of the time, 99.9% is electrons in a metal wire. but there are times where a conductor can produce a significant current of protons. so the conventional current refers to the flow of protons (+ve particles), or backward flow of electrons (-ve particles), since a back electron equals the charge of a foward flowing proton. electron current is the other way. :)
 

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