A macromolecule is a molecule with lots and lots of atoms. (i.e. protein, nucleic acid...) A network solid is <span>is a chemical compound where the atoms are "bonded by covalent bonds in a continuous </span>network<span> extending throughout the material." A single grain of sand consists of, on average, </span><span>~50,000,000,000,000,000,000 atoms. That's A LOT. However, these atoms do bond in network covalent bonds. But that means it's a covalent network solid. The short answer is that sand is both a </span><span>macromolecular substance as well as a covalent network solid, so I would go with it's macromolecular but you can interpret that the way you want.</span>
