ABSTRACT
Atoms and molecules, even uncharged ones, are attracted to each other. They can form noncovalent as well as covalent bonds. We know this because they condense into liquids and solids at low temperatures. Noncovalent interactions between uncharged particles are relatively weak and short-ranged, but they are the fundamental driving forces for much of chemistry, physics, and biology. These intermolecular interactions can be understood through measurements of the pressures of nonideal gases. The laws of electrostatics explain the attractions between charged atoms, say Na+ and Cl−. But what forces cause neutral atoms to bond together noncovalently? To a first approximation, the bonding between neutral molecules can also be explained by electrostatic interactions. Even when the atoms have no net charge, they have charge distributions and polarizabilities, which lead to weak attractions.
