Final answer:
Macroscopic properties such as boiling and melting points, viscosity, density, and the structures of DNA and proteins are largely dictated by the intermolecular forces between molecules.
Step-by-step explanation:
Many macroscopic properties are determined by the type of intermolecular forces between molecules. These forces impact various physical properties such as boiling and melting points, viscosity, solubility, and density. For instance, molecules within a liquid boil when they have enough thermal energy to overcome the intermolecular attractive forces that hold them together. This results in the formation of vapor bubbles within the liquid. Conversely, solids melt when molecules acquire enough thermal energy to break free from the forces that keep them in place within the solid structure.
Moreover, the three-dimensional shapes and functions of DNA and protein molecules are influenced by these non-covalent bonds, as they help determine the molecular geometry and interactions critical for biochemical functions. Physical properties can vary even among substances with similar molar masses, indicating that intermolecular forces play a more dominant role than molecular weight in determining these properties.