electrons in conductors

[Guest mikaela]

i remembered a question that goes somthing like this:

 

electrons have speed as much as 10 ^6 m/s. Why won't these electrons fly out of the conductor?

[ecoli]

electrostatic forces.

[reverse]

when you get to the teeny weeny level of reality you find that the particles all have a deal going about how they will relate.

 

You cant think about them as if they behaved the same way as people sized objects.

 

 

what I like is when an electron wants to shift to another level of energy you can get a photon to fly off.

 

that's kind of cool.

 

and kind of what you want to happen.

[5614]

Becuase it is bonded to the atom with forces which are far more powerful than it's kinetic energy.

 

Also because an electron has such little mass it has little momentum. It might be have a high speed or velocity, but it's momentum is small, the forces bonding it to the nucleus of the atom are far stronger.

[YT2095]

they CAN and do sometimes "Fly off" the conductor, although it`s not just a function of their speed, but Voltage.

 

that`s how electrical arcs occur and how an Electron gun works in the back of your TV, sharp points in a conductor are particularly "Leaky" to HT electricity and are to be avoided for this reason.

 

yes, what you mentioned Does happen

[reverse]

Isn't the air ionised thus becoming a conductor?

 

and in the electron gun, arent the electrons tricked out by a nice tempting charged grid.

 

sure they leave potential orbit, but can you really think of them as flying off?

[YT2095]

sure, although I`de probably word it a little better than the OP.

 

it`s how air Ionisers work too, granted some occurs in air, but will occur equaly well (if not better) in a Vacuum too

 

edit: probably a better way to demonstrate this would be to think of how the cathode works in a thermionic valve. if it`s not overdriven the electrons will flow from the cathode to the plate (in a diode) and you`ll see nothing happen between them, but you can be sure electrons are passing across the Vacuum gap

 

double edit: think about corona discharge too, as I said, it`s mainly on HT equipment that it occurs and your AA batteries from the corner shop are not exactly going to display this, but the HT lead at the back of a TV set will (DON`T even try it!).