electrons

if electric current is the flow of electrons, and electrons are already present in a conductor and not generated by a source such as a generator or battery. then how is it possible for an atom to contiuously loose electrons? will a conductor eventually loose all electrons? if not how are they continuously there to "flow"? if all current eventually goes to ground then what? my mind is about to explode, please explain.

thank you

 

[cbarn24050]

Hi, current flow is the movement of electrons around a circuit.They are not created or destroyed, just pushed round in circles.

 

[Bung]

The key is "current is the flow of electrons..." - they are there all the time, but only become current when they go walk-about under the influence of an emf (potential difference).

bung

 

[MrWizard]

Although electrons are present in the conductor, electrons won't flow, or move from atom to atom until the conductor sees a potential difference across itself, (voltage). With a voltage applied, one end of the conductor appears negative while the other end appears positive. Electrons are pushed in and pulled out at the same time as they attempt to find a balance. Once the potential is removed current flow will cease.

 

[maximka]

Electrons will only flow (in a steady state) if the circuit is closed. Earth is a conductor, and therefore, while "draining" electrones at one end of the circuit, it actually "returns" them at the other end. Number of free electrones in a wire will forever remain the same, i. e. will be only defined by the property of the wire.

 

[nbucska]

Flow == collective motion. The electrons' random motion
is the noise-current. <nbucska@pcperipherals.com>

 

[dpc]

In materials that are good conductors, such as metals, the atoms have electrons that are very loosely bound to the nucleus. It is these &quot;free&quot; electrons that sort of push each other down the conductor.

An interesting calculation is to determine the speed of an individual electron moving down a conductor for a given current flow. As I recall, they aren't really moving all that fast.

Materials that are good insulators have electrons that are tightly bound to the nuclei and therefore produce little current flow.

 

[mchenney]

1) Each atom trys to keep the same number of electrons circling it's nuculus, staying in balance with other surrounding atoms. But the actual number is dynamic.

2) An outer ring FREE electron flys out of orbit in one atom and FLOWs to another atom that attracts and captures it into orbit. A better conductor a material is the more this happens when there are more electrons in one area than another. Missing electron positions in an atom's orbit are called HOLES, that FREE electrons can fill. The more electrons an atom has, the less attraction it has on the outer orbit electrons of other atoms.

3) THE FLOW is the accumaltive flow of billions of electrons from billions of atoms, one electron one atom to another atom, not one electron going full circle, but billions of free electrons moving, each from one atom to the next atom with a hole, at the same time. Think of it like toppling a string domino's, with respect to flow. If an atom attacts another's electron to its HOLE, the other atom now has a HOLE to attract some third atoms electron...and on and on.

4) The area / atoms with holes (less electrons in orbit, that attracts FREE electrons)is +, thus electron flow is - to +.





Dennis McHenney
mchenney@mindspring.com

&lt;dmchenney@merkle-korff.com&gt;

&lt;mchenney@mindspring.com&gt;