Question

# Which of the following is a molecular solid? A. DiamondB. GraphiteC. IceD. Quartz

- Ice: Ice is an example of Hydrogen Bonded Molecular Solids. Molecules of these solid forms polar covalent bonds between H and electronegative elements like $\text{F ,O or N}$ atoms. Ice$\text{(}{{\text{H}}_{2}}\text{O)}$ is bounded by strong hydrogen bonding. It is a non-conductor of electricity. It is a volatile liquid or soft solid under room temperature.
- Quartz: Quartz is a strong substance because its molecules form network covalent structures. The structure forms a lattice-like structure. It is composed of oxygen and silicon atoms in silicon-oxygen tetrahedra ($\text{Si}{{\text{O}}_{4}}$). Each oxygen atom is shared between two tetrahedral atoms, making quartz as $\text{Si}{{\text{O}}_{2}}$. It is used to make oscillators for clocks and cell phones.
Note: Any type of structure can be categorized to which solid it belongs by knowing the type of bond it forms. Like, Ionic solids have its constituent particles as ions which are bounded by electrostatic forces. Examples of Ionic solids are $\text{NaCl,MgO}$. This is how a structure can be categorized as which type of solid it is.