These materials are characterized by constituent molecules held together by relatively weak intermolecular forces. These forces, which include van der Waals forces, dipole-dipole interactions, and hydrogen bonds, are significantly weaker than the intramolecular forces (covalent or ionic bonds) that hold the atoms together within the molecules themselves. A common example includes ice, where water molecules are linked via hydrogen bonds, giving it a defined structure at low temperatures.
The significance of understanding these materials lies in their varied properties. Due to the weak intermolecular forces, these solids typically exhibit low melting and boiling points, as less energy is required to overcome the interactions between the molecules. They are often poor conductors of electricity and heat because electrons are strongly localized within the molecules and are not readily available for transport. Historically, the study of these solids has contributed to a broader understanding of intermolecular forces and their influence on the macroscopic properties of matter.
