Between-molecules

Referring to interactions or spaces existing or occurring in the area located amongst individual molecules. These are often weak, non-covalent forces which govern the physical properties of matter, like melting point, boiling point, solubility and surface tension. They are crucial in determining the structure and behavior of substances, playing a significant role in phenomena ranging from the formation of liquids and solids to biological processes like protein folding and enzyme-substrate interactions. These include forces like van der Waals forces (London dispersion, dipole-dipole) and hydrogen bonds, distinct from the intramolecular forces (covalent, ionic) holding atoms together within a single molecule. The strength and type of these interactions vary with the size, shape, and polarity of the molecules involved. They dictate how molecules arrange and interact in different phases of matter, greatly impacting various chemical and physical properties of substances.

Between-molecules meaning with examples

• The unusually high boiling point of water is a direct result of strong Between-molecules hydrogen bonds. These bonds create an attractive force, requiring more energy to break and change the state from liquid to gas.
• In a nonpolar substance like methane, the primary Between-molecules interactions are weak London dispersion forces. These forces are easily overcome, leading to methane’s low melting and boiling points.
• The viscosity of a liquid is determined by the strength of the Between-molecules forces. Stronger interactions, such as those found in glycerol (due to hydrogen bonding), result in higher viscosity.
• The solubility of a solute in a solvent is largely determined by the compatibility of the Between-molecules interactions of the solute with those of the solvent. Like dissolves like.
• The arrangement of molecules in a crystal lattice is dictated by the pattern established by the nature of Between-molecules forces, and will affect the materials final mechanical properties.