Why is copper a good conductor?
One loose outer electron per atom makes a sea of free electrons, and an orderly lattice lets them flow.
Transcript
A copper atom has twenty nine electrons, but only one sits in its outer shell.
That lone electron is weakly bound, so it is easy to pull free.
In solid copper, every atom shares its electron, forming a sea of free electrons.
That is about one free electron per atom: a huge number of charge carriers.
In rubber, electrons stay bound to their atoms, so nothing flows.
In copper, electrons drift through a tidy lattice, with few collisions.
Only silver beats it, but copper is cheaper, and easy to draw into wire.
Lots of free electrons, and an orderly lattice to flow through. That is why copper is a great conductor.
