What gives metals their reflective characteristics?


What gives metals their reflective characteristics?

In: Physics

Actually this is NOT totally known as far as I know. But scientists suspect that it has to do with the free electrons (electron sea). Basically when electrons are bounded in orbits they can only absorb specific wavelengths of photons and hence, emit only those wavelenghts back.

In case of metals, the electrons are free and can absorb virtually any photon in the visible light spectrum and emit them back. So basically they reflect back whatever they absorb and voila.. act like mirrors on a level.

the electronic conductance. Light is an electric field, and electrons in the metal can absorb that very well to the point that light cannot propagate in the metal.
In a medium where light cannot propagate at all, (… enter ELI5 description of impedance mismatch here…) it eventually gets reflected.

Think of a wave hitting the shoreline. Since the wave can’t keep moving in the direction of the shore, but the energy has to go somewhere, it ends up going backwards.

This is the principle here – metals are conductors, which physics understands as that the electric field can only exist on their surface. So the light hitting the metal is like the wave hitting the shore – and it ends up being almost entirely reflected.