Why is copper such a good conductor, although it has only one free electron?And why is Nichrome a relatively poor conductor?
Copper has 29 orbiting electrons. 28 of then are fixed to the atom in their respective orbits. The 29th is a free electron and wanders throughout the metal. The atoms in copper vibrate around a fixed position, with 28 of their electrons orbiting around them. The spaces between the atoms are filled with the free electrons - one from each atom. They collide with each other, and other atoms, and behave like the particles of a gas, i.e. they have random (chaotic) motion. However, when a potential difference is applied across the copper, as well as moving at random at high speed as before, they also drift very slowly towards the +ve terminal. (An electrical current flows very slowly). An electrical current is just the slow drift of free electrons in those materias which have free electrons. If there are no free electrons, then there is no current. Fewer free electrons means a smaller current ( i.e more electrical resistance, like Nichrome.) Insulators can often be made to conduct. Although they normally have few free electrons, or none, the application of a large enough voltage will forcibly remove outer electrons from atoms, and make then free.
Additionally to what she said, Copper is a very efficient conductor of electricity, heat and charges beacuse of its structure. Metals are good conductors.
Copper is a metal, all metals are good conductors of electricity. Metals are good conuctors of electicity because they have possitive metal ions free in a sea of electrons which carry the electric charge hence metals are considered to be good conductors of electricity.
