Most covalent compounds do not conduct electricity in any form. However,graphite(which is an allotrope of carbon),can do so because of it special structure. So if this is an M.C.Q the answer will be solids. If it's an explanation answer,then you have to write the above and that the 4 outer electrons of the carbon atoms form bonds with only 3 other,so the free electron can move about the lattice carrying charge. Hope this helps!!!