Glass is a typical insulator: electrons inside their atoms has band gaps, which are setting limits for low-frequency photons and prohibits energy conveying for them.
Therefore, light just passes through (transparency).
Metals, on the other hand, as conductors has NO band gaps, so in theory (as I took it) any photon regardless of its frequency may give away its energy to electrons.
My question is: does any photon therefore will (definitely) excite such electrons?
Simply speaking: are there any quantum mechanical processes\phenomena that allows a single photon pass through "NO band gaping" orbitals in conductors? And does these processes\phenomena (if there are any) depends on photon's frequency?