Major doubt in electronics?

Question

flow of electrons is current,matter consisits of atoms(electrons,protons and neutrons).
if current passes through matter like wire,movement of electrons takes place in matter then,how wire was stable without any decomposition because some of it's electrons flow away?

Answer 1

new electons immediately come in to fill their place, remember electrons aren't ATTACHED, they're just flying around NEAR, orbiting.

Answer 2

You don't need exactly one electron per proton to keep chemical bonds stable. Just think of ionic compounds which are missing one to up to half a dozen electrons and are still perfectly stable.

With metals it is the same. You can remove many electrons from a macroscopic conductor and not change its chemical structure much. By the time you would get to the number it would take to actually disintegrate this thing, you would have charged the metal to billions of volts, probably more.

And the other people are correct, of course. In a conductor which is part of an electric circuit, there are an equal number of electrons going in as are going out.

Answer 3

The first answer is kind of right. There are electrons remotely attached to atomic cores. That is, when the atoms move; so do their herd of electrons. These are not the electrons that move through a charged wire and result in a current however.

Free electrons also exist in metals. They are unattached; so when a potential (voltage) is put across a wire, they move right along from the minus terminal to the plus one. As electrons disappear into the plus side, more are appearing from the power source on the minus side.

[NB: If you are an electrical engineer student, you probably have used the plus to minus convention for current flow. But we physicists know better than that.]

Free electrons do not move at the speed of light as you might think. In fact they kind of drift from minus to plus at a comparatively slow velocity. Although off the top of my head I've forgotten what a typical electron drift speed is, I remember it as being a matter of only a few meters or centimeters per sec.

So why do light bulbs come on seemingly immediately when a switch is thrown? Because the energy that lights that bulb comes from the wave speed of those electrons. And the wave front does travel at light speed depending on the medium it is traveling through.

So, bottom line, the free electrons in a charged wire are continually being replaced by whatever the power source might be...generator, battery, etc. Which is why, in the case of batteries, we have to replace that power source now and then. And those non-free electrons belonging to the metal atoms of the wire do not move and so the metal remains stable.