1 point The addition of an interstitial element to a metal the overall hardness and strength while the ductility. increases, increasing Adding an interstitial element to a metal has no affect on its properties. increases, decreasing decreases, increasing decreases, decreasing 0.5 points The electronic structure of a solid substance consists of a valence band that is completely filled with electrons and there is a large energy gap to the next set of orbitals, then this substance will be a(n) nonmetal semiconductor alloy conductor insulator