Plenty of Electrons

Most recent answer: 10/22/2007

Will the copper ever run out of electrons?
- matt glynn (age 19)
iowa city iowa
Nope.  There are plenty to go around.  Pun intended. 
The reason is that if a voltage is induced in a piece of copper wire by moving it in a magnetic field a current is produced only if there is a path from one end of the wire to the other, say
through a light bulb.  So the loss of electrons on one side of the wire is replenished by the influx of electrons on the other side.  If there is no completed circuit some electrons will bunch up on one end of the piece of copper and produce a static voltage.  The net number of electrons
in the piece of wire remains constant.


(published on 10/22/2007)