Can somebody explain in atomic terms why most metals appear silvery-grey in colour, and what are copper and gold doing differently?

peasypod

Gmack, it's because they have free electrons at the surface. [Jul 17 04 9:59 PM] peasypod writes: If the efficiency of absorption and reemission is approximately equal at all optical energies, then the different colors in white light will be reflected equally well, thus leading to the "silvery" color of polished iron and silver surfaces. However, if the efficiency decreases with increasing energy, as is the case for gold and copper, the reduced reflectivity at the blue end of the spectrum results in yellow and reddish colors, respectively. The efficiency of this process depends on the selection rules that apply to the atomic orbitals from which the energy band had formed. Not a trivial excercise gmack.... Jul 17 04, 8:35 PM