Final answer:
The binding in quartz is described as covalent, and it is a covalent network solid with a high melting point characteristic of strong covalent bonds throughout the crystal. correct option is C.
Step-by-step explanation:
The binding in quartz (SiO2) is best described as covalent. Quartz is a covalent network solid, which means that its structure consists of atoms covalently bonded together in a continuous network. In the case of quartz, each silicon atom is bonded to four oxygen atoms, forming SiO4 tetrahedra. This covalent bonding extends throughout the entire crystal, making each piece of quartz essentially a single giant molecule. Due to the extensive network of covalent bonds, covalent network solids like quartz have very high melting points. Quartz has a melting point of approximately 1650°C, indicative of the strong covalent bonds that must be broken for it to transform into a liquid.