Here's what I what to know… Atoms have a nucleus that's positively charged and the negative electrons flow around it. Well when you pull the negative electrons off the atom where do the new electrons come from? Why does copper not ever run out of electrons? Who is making the new negative electrons? I hope you see what I'm saying and give me an answer. Thanks … Won't copper run out free of electrons?
[Physics] Where do free electrons come from
electrons
Related Solutions
Not to worry :).
The electrons that come out with rubbing are electrons that are loosely bound to the material, from the last energy level of the atoms. To get a second one out from the same atom would take a lot more energy, so it usually does not happen. Not to forget that there are a large number of atoms ( about 10^23/mole) making up any matter so positive charges can build up by enough of them having one electron missing.
The positively charged surface slowly re absorbs electrons from the molecules of the air in the atmosphere, or from you when a spark goes off.
You are right, the planetary model of the atom does not make sense when one considers the electromagnetic forces involved. The electron in an orbit is accelerating continuously and would thus radiate away its energy and fall into the nucleus.
One of the reasons for "inventing" quantum mechanics was exactly this conundrum.
The Bohr model was proposed to solve this, by stipulating that the orbits were closed and quantized and no energy could be lost while the electron was in orbit, thus creating the stability of the atom necessary to form solids and liquids. It also explained the lines observed in the spectra from excited atoms as transitions between orbits.
If you study further into physics you will learn about quantum mechanics and the axioms and postulates that form the equations whose solutions give exact numbers for what was the first guess at a model of the atom.
Quantum mechanics is accepted as the underlying level of all physical forces at the microscopic level, and sometimes quantum mechanics can be seen macroscopically, as with superconductivity, for example. Macroscopic forces, like those due to classical electric and magnetic fields, are limiting cases of the real forces which reign microscopically.
Best Answer
In order for a current to flow steadily, you have to connect the conductor (copper in your case) to positive and negative poles of a battery. Then the electrons go from the copper to the positive pole of the battery - but - they are replaced by the electrons which come from the negative pole of the battery. Thus, the free electrons in copper are only needed to make it possible for current to flow, the copper itself is not depleted of electrons.