Concept:Molecular solids consist of discrete, neutral molecules held together in a lattice by weak intermolecular forces (Van der Waals forces, dipole-dipole, or hydrogen bonds).
Solution:- Carbon dioxide (\( \text{CO}_2 \)) is a discrete, non-polar covalent molecule.
- When cooled sufficiently, it freezes to form solid \( \text{CO}_2 \) (commonly known as dry ice).
- In this solid state, independent \( \text{CO}_2 \) molecules occupy the lattice points and are held together only by weak London dispersion forces.
- Therefore, \( \text{CO}_{2(s)} \) is a classic example of a molecular solid.
Why other options are incorrect:- C, D: \( \text{CsF} \) and \( \text{NaCl} \) are composed of a metal and a non-metal, forming a lattice of cations and anions held by strong electrostatic forces. They are ionic solids.
- A: Aluminum nitride usually forms extended covalent/ionic networks, not discrete molecular solids.
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