1. Explain why metallic binding leads to a close-packed arrangement of atoms; i.e., explain why the lowest energy in metallic binding corresponds to the greatest number density of atoms.
2. Why are metallic solids mostly opaque, covalent solids sometimes opaque, and ionic solids hardly ever opaque to visible radiation?
3. Of the four types of binding in solids discussed in the text, which one (or ones) is most likely to produce an insulator?
A conductor
A semiconductor