Van der Waals force

In <a href="/facts/Molecular_physics/ArRhIjdY">molecular physics</a> and <a href="/facts/Chemistry/SrNqkGVm">chemistry</a>, the van der Waals force (sometimes van der Waals' force) is a distance-dependent interaction between <a href="/facts/Atom/FoQ4kGN5">atoms</a> or <a href="/facts/Molecule/N9ljSfFq">molecules</a>. Unlike <a href="/facts/Ionic_bond/R6nUJI5u">ionic</a> or <a href="/facts/Covalent_bond/EzMLf3Pz">covalent bonds</a>, these attractions do not result from a <a href="/facts/Chemical_bond/ArNUMnIB">chemical electronic bond</a>; they are comparatively weak and therefore more susceptible to disturbance. The van der Waals force quickly vanishes at longer distances between interacting molecules.
Named after Dutch physicist <a href="/facts/Johannes_Diderik_van_der_Waals/WCbnoblK">Johannes Diderik van der Waals</a>, the van der Waals force plays a fundamental role in fields as diverse as <a href="/facts/Supramolecular_chemistry/wwUfD0fk">supramolecular chemistry</a>, <a href="/facts/Structural_biology/XRkPtHYv">structural biology</a>, <a href="/facts/Polymer_science/ulLpdDyQ">polymer science</a>, <a href="/facts/Nanotechnology/Co4FFNfY">nanotechnology</a>, <a href="/facts/Surface_science/WTENdutJ">surface science</a>, and <a href="/facts/Condensed_matter_physics/EBVI5nmL">condensed matter physics</a>. It also underlies many properties of <a href="/facts/Organic_chemistry/djxhxaNg">organic compounds</a> and <a href="/facts/Molecular_solid/X952jWbq">molecular solids</a>, including their <a href="/facts/Solubility/kLE9h3Jb">solubility</a> in <a href="/facts/Chemical_polarity/KlIJ0zjB">polar and non-polar</a> media.
If no other <a href="/facts/Force/533Q1uzq">force</a> is present, the distance between atoms at which the force becomes repulsive rather than attractive as the atoms approach one another is called the van der Waals contact distance; this phenomenon results from the mutual repulsion between the atoms' <a href="/facts/Atomic_orbital/tKhgl6mL">electron clouds</a>.
The van der Waals forces are usually described as a combination of the <a href="/facts/London_dispersion_force/zU842d26">London dispersion forces</a> between "instantaneously induced <a href="/facts/Dipole/G1vRqruD">dipoles</a>", <a href="/facts/Debye_force/xIcFMvL7">Debye forces</a> between permanent dipoles and induced dipoles, and the <a href="/facts/Keesom_force/xIcFMvL7">Keesom force</a> between permanent <a href="/facts/Molecular_dipole_moment/G1vRqruD">molecular dipoles</a> whose rotational orientations are dynamically averaged over time.

Van der Waals force open-in-new

Van der Waals force