When a light wave of the form E=E0eiω hits the surface of a metal, the refractive index if given(considering restoring force of metal atoms and damping equal to 0), by n2=1-p2/ω2 where p=plasma frequency and ω= frequency of the wave. In the case where n2<0, n is complex. and hence the light wave is completely damped. What my question is, does that meant that the wave is reflected back or, does it mean that the energy is lost as heat? Also, to explain the case of an n2 > 0, an example of the ionosphere is often quoted where n keeps varying with altitude and hence radio waves that we send from the earth's surface turn and get reflected back to the surface. Does that mean that more the substance is metallic, more it acts like a reflector? At this point I'm pretty much confused about what I even want to ask. Please enlighten. Thank you.