TheInfoList

An intermolecular force (IMF) (or secondary force) is the force that mediates interaction between molecules, including the which act between atoms and other types of neighboring particles, e.g.
atom An atom is the smallest unit of ordinary matter In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of ato ...

s or
ion An ion () is an atom An atom is the smallest unit of ordinary matter In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ...
s. Intermolecular forces are weak relative to
intramolecular force An intramolecular force (or primary forces) is any force In physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion and behavior through Spacetime, sp ...
s – the forces which hold a molecule together. For example, the
covalent bond A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they s ...
, involving sharing electron pairs between atoms, is much stronger than the forces present between neighboring molecules. Both sets of forces are essential parts of
force fields In speculative fiction, a force field, sometimes known as an energy shield, force shield, force bubble, defence shield or deflector shield, is a barrier made of things like energy, negative energy, dark energy, electromagnetic fields, gravitationa ...
frequently used in
molecular mechanics is used to minimize the bond stretching energy of this ethane molecule. Molecular mechanics uses classical mechanics to model molecular systems. The Born–Oppenheimer approximation is assumed valid and the potential energy of all systems is cal ...
. The investigation of intermolecular forces starts from macroscopic observations which indicate the existence and action of forces at a molecular level. These observations include non-ideal-gas thermodynamic behavior reflected by
virial coefficient Virial coefficients B_i appear as coefficients in the virial expansion of the pressure of a many-particle system in powers of the density, providing systematic corrections to the ideal gas law Image:Ideal gas isotherms.svg, Isothermal process, I ...
s,
vapor pressure 280px, The ''pistol test tube'' experiment. The tube contains alcohol and is closed with a piece of cork. By heating the alcohol, the vapors fill in the space, increasing the pressure in the tube to the point of the cork popping out. Vapor pre ...

,
viscosity The viscosity of a is a measure of its to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, has a higher viscosity than . Viscosity can be conceptualized as quantifying the inter ...

, superficial tension, and absorption data. The first reference to the nature of microscopic forces is found in
Alexis Clairaut Alexis Claude Clairaut (; 13 May 1713 – 17 May 1765) was a French mathematician, astronomer, and geophysicist. He was a prominent Newtonian whose work helped to establish the validity of the principles and results that Sir Isaac Newton ...
's work ''Théorie de la figure de la Terre,'' published in Paris in 1743. Other scientists who have contributed to the investigation of microscopic forces include:
Laplace Pierre-Simon, marquis de Laplace (; ; 23 March 1749 – 5 March 1827) was a French scholar and polymath A polymath ( el, πολυμαθής, ', "having learned much"; Latin Latin (, or , ) is a classical language belonging to the I ...

,
Gauss Johann Carl Friedrich Gauss (; german: Gauß ; la, Carolus Fridericus Gauss; 30 April 177723 February 1855) was a German mathematician This is a List of German mathematician A mathematician is someone who uses an extensive knowledge of m ...

, and
Boltzmann Ludwig Eduard Boltzmann (; 20 February 1844 – 5 September 1906) was an Austria Austria (, ; german: Österreich ), officially the Republic of Austria (german: Republik Österreich, links=no, ), is a landlocked Eastern Alps, East Al ...
. Attractive intermolecular forces are categorized into the following types: *
Hydrogen bond A hydrogen bond (or H-bond) is a primarily electrostatic Electrostatics is a branch of physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical science is that department ...

ing *Ion–induced dipole forces *Ion–dipole forces *
van der Waals force Microfiber cloth makes use of London-dispersion force to remove dirt without scratches. In molecular physics Molecular physics is the study of the physical properties of molecule File:Pentacene on Ni(111) STM.jpg, A scanning tunneling micr ...
s –
Keesom force Intermolecular forces (IMF) (or secondary forces) are the forces which mediate interaction between molecules, including forces of attraction or repulsion which act between atoms and other types of neighboring particles, e.g. atom An atom is the ...
,
Debye force Intermolecular forces (IMF) (or secondary forces) are the forces which mediate interaction between molecules, including forces of attraction or repulsion which act between atoms and other types of neighboring particles, e.g. atom An atom is the ...
, and
London dispersion force London dispersion forces (LDF, also known as dispersion forces, London forces, instantaneous dipole–induced dipole forces, Fluctuating Induced Dipole Bonds or loosely as van der Waals forces) are a type of force acting between atom An atom ...
Information on intermolecular forces is obtained by macroscopic measurements of properties like viscosity, pressure, volume, temperature (PVT) data. The link to microscopic aspects is given by
virial coefficient Virial coefficients B_i appear as coefficients in the virial expansion of the pressure of a many-particle system in powers of the density, providing systematic corrections to the ideal gas law Image:Ideal gas isotherms.svg, Isothermal process, I ...
s and
Lennard-Jones potential The Lennard-Jones potential (also termed the LJ potential or 12-6 potential) is an intermolecular pair potential. Among the Interatomic potential, intermolecular potentials, the Lennard-Jones potential is the potential that has been studied most e ...
s.

# Hydrogen bonding

A ''hydrogen bond'' is an extreme form of dipole-dipole bonding, referring to the attraction between a
hydrogen Hydrogen is the chemical element with the Symbol (chemistry), symbol H and atomic number 1. Hydrogen is the lightest element. At standard temperature and pressure, standard conditions hydrogen is a gas of diatomic molecules having the che ...

atom that is bonded to an element with high electronegativity, usually
nitrogen Nitrogen is the chemical element upright=1.0, 500px, The chemical elements ordered by link=Periodic table In chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science ...

,
oxygen Oxygen is the chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic table, The periodic table of the chemical elements In chemistry, an element is a pure substance consisting only of atoms that all have the same ...

, or
fluorine Fluorine is a chemical element with the Chemical symbol, symbol F and atomic number 9. It is the lightest halogen and exists at Standard conditions for temperature and pressure, standard conditions as a highly toxic, pale yellow Diatomic molecule ...

and another of these same elements. The hydrogen bond is often described as a strong electrostatic dipole–dipole interaction. However, it also has some features of covalent bonding: it is directional, stronger than a
van der Waals force Microfiber cloth makes use of London-dispersion force to remove dirt without scratches. In molecular physics Molecular physics is the study of the physical properties of molecule File:Pentacene on Ni(111) STM.jpg, A scanning tunneling micr ...
interaction, produces interatomic distances shorter than the sum of their van der Waals radii, and usually involves a limited number of interaction partners, which can be interpreted as a kind of valence. The number of Hydrogen bonds formed between molecules is equal to the number of active pairs. The molecule which donates its hydrogen is termed the donor molecule, while the molecule containing lone pair participating in H bonding is termed the acceptor molecule. The number of active pairs is equal to the common number between number of hydrogens the donor has and the number of lone pairs the acceptor has. Though both not depicted in the diagram, water molecules have two active pairs, as the oxygen atom can interact with two hydrogens to form two hydrogen bonds. Intermolecular hydrogen bonding is responsible for the high boiling point of
water Water (chemical formula H2O) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known li ...

(100 °C) compared to the other
group 16 hydrides A group is a number of people or things that are located, gathered, or classed together. Groups of people * Cultural group, a group whose members share the same cultural identity * Ethnic group, a group whose members share the same ethnic identi ...
, which have little capability to hydrogen bond. Intramolecular hydrogen bonding is partly responsible for the
secondary Secondary is an adjective meaning "second" or "second hand". It may refer to: * Secondary (chemistry), term used in organic chemistry to classify various types of compounds * The group of (usually at least four) defensive backs in gridiron football ...

,
tertiary Tertiary ( ) is a widely used but obsolete term for the Period (geology), geologic period from 66 million to 2.6 million years ago. The period began with the demise of the non-bird, avian dinosaurs in the Cretaceous–Paleogene extincti ...

, and
quaternary structure Biomolecular structure is the intricate folded, three-dimensional shape that is formed by a molecule File:Pentacene on Ni(111) STM.jpg, A scanning tunneling microscopy image of pentacene molecules, which consist of linear chains of five carbon ...

s of
protein Proteins are large biomolecule , showing alpha helices, represented by ribbons. This poten was the first to have its suckture solved by X-ray crystallography by Max Perutz and Sir John Cowdery Kendrew in 1958, for which they received a No ...

s and
nucleic acid Nucleic acids are biopolymer Biopolymers are natural polymer A polymer (; Greek ''wikt:poly-, poly-'', "many" + ''wikt:-mer, -mer'', "part") is a Chemical substance, substance or material consisting of very large molecules, or macromolecule ...

s. It also plays an important role in the structure of
polymers A polymer (; Greek ''poly- Poly, from the Greek :wikt:πολύς, πολύς meaning "many" or "much", may refer to: Businesses * China Poly Group Corporation, a Chinese business group, and its subsidiaries: ** Poly Property, a Hong Kong inco ...

, both synthetic and natural.

# Ionic bonding

The attraction between cationic and anionic sites is a noncovalent, or intermolecular interaction which is usually referred to as ion pairing or salt bridge. It is essentially due to electrostatic forces, although in aqueous medium the association is driven by entropy and often even endothermic. Most salts form crystals with characteristic distances between the ions; in contrast to many other noncovalent interactions, salt bridges are not directional and show in the solid state usually contact determined only by the van der Waals radii of the ions. Inorganic as well as organic ions display in water at moderate ionic strength I similar salt bridge as association ΔG values around 5 to 6 kJ/mol for a 1:1 combination of anion and cation, almost independent of the nature (size, polarizability, etc.) of the ions. The ΔG values are additive and approximately a linear function of the charges, the interaction of e.g. a doubly charged phosphate anion with a single charged ammonium cation accounts for about 2x5 = 10 kJ/mol. The ΔG values depend on the ionic strength I of the solution, as described by the Debye-Hückel equation, at zero ionic strength one observes ΔG = 8 kJ/mol.

# Dipole–dipole and similar interactions

## Regular dipole

Dipole–dipole interactions are electrostatic interactions between molecules which have permanent dipoles. This interaction is stronger than the London forces but is weaker than ion-ion interaction because only partial charges are involved. These interactions tend to align the molecules to increase attraction (reducing
potential energy In physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors. Common types of potential energy include the gravitational potentia ...

). An example of a dipole–dipole interaction can be seen in
hydrogen chloride The compound Compound may refer to: Architecture and built environments * Compound (enclosure), a cluster of buildings having a shared purpose, usually inside a fence or wall ** Compound (fortification), a version of the above fortified with d ...

(HCl): the positive end of a polar molecule will attract the negative end of the other molecule and influence its position. Polar molecules have a net attraction between them. Examples of polar molecules include
hydrogen chloride The compound Compound may refer to: Architecture and built environments * Compound (enclosure), a cluster of buildings having a shared purpose, usually inside a fence or wall ** Compound (fortification), a version of the above fortified with d ...

(HCl) and
chloroform Chloroform, or trichloromethane, is an organic compound with formula CH Cl3. It is a colorless, strong-smelling, dense liquid that is produced on a large scale as a precursor to PTFE Polytetrafluoroethylene (PTFE) is a synthetic fluoropoly ...

(CHCl3). : Often molecules contain dipolar groups of atoms, but have no overall
dipole momentDipole moment may refer to: *Electric dipole moment, the measure of the electrical polarity of a system of charges **Transition dipole moment, the electrical dipole moment in quantum mechanics **Molecular dipole moment, the electric dipole moment o ...
on the molecule as a whole. This occurs if there is symmetry within the molecule that causes the dipoles to cancel each other out. This occurs in molecules such as
tetrachloromethane Carbon tetrachloride, also known by many other names (such as tetrachloromethane, also recognised by the IUPAC, carbon tet in the cleaning industry, Halon-104 in firefighting, and Refrigerant-10 in HVACR) is an organic compound , CH4; is among ...
and
carbon dioxide Carbon dioxide (chemical formula A chemical formula is a way of presenting information about the chemical proportions of s that constitute a particular or molecule, using symbols, numbers, and sometimes also other symbols, such as pare ...

. The dipole–dipole interaction between two individual atoms is usually zero, since atoms rarely carry a permanent dipole. These forces are discussed further in the section about the Keesom interaction, below.

## Ion–dipole and ion–induced dipole forces

Ion–dipole and ion–induced dipole forces are similar to dipole–dipole and dipole–induced dipole interactions but involve ions, instead of only polar and non-polar molecules. Ion–dipole and ion–induced dipole forces are stronger than dipole–dipole interactions because the charge of any ion is much greater than the charge of a dipole moment. Ion–dipole bonding is stronger than hydrogen bonding. An ion–dipole force consists of an ion and a polar molecule interacting. They align so that the positive and negative groups are next to one another, allowing maximum attraction. An important example of this interaction is hydration of ions in water which give rise to hydration enthalpy. The polar water molecules surround themselves around ions in water and the energy released during the process is known as hydration enthalpy. The interaction has its immense importance in justifying the stability of various ions (like Cu2+) in water. An ion–induced dipole force consists of an ion and a non-polar molecule interacting. Like a dipole–induced dipole force, the charge of the ion causes distortion of the electron cloud on the non-polar molecule.

# Van der Waals forces

The van der Waals forces arise from interaction between uncharged atoms or molecules, leading not only to such phenomena as the cohesion of condensed phases and physical absorption of gases, but also to a universal force of attraction between macroscopic bodies.

## Keesom force

The first contribution to van der Waals forces is due to electrostatic interactions between rotating permanent dipoles, quadrupoles (all molecules with symmetry lower than cubic), and multipoles. It is termed the ''Keesom interaction'', named after
Willem Hendrik Keesom Willem Hendrik Keesom () (21 June 1876, Texel Texel (; Texels dialect: ) is a municipality A municipality is usually a single administrative division having Municipal corporation, corporate status and powers of self-government or jurisdic ...
. These forces originate from the attraction between permanent dipoles (dipolar molecules) and are temperature dependent. They consist of attractive interactions between dipoles that are
ensemble Ensemble may refer to: Art * Musical ensemble * Ensemble cast (drama, comedy) * Ensemble (musical theatre), also known as the chorus * Ensemble (band), a project of Olivier Alary * Ensemble (album), ''Ensemble'' (album), Kendji Girac 2015 album ...
averaged over different rotational orientations of the dipoles. It is assumed that the molecules are constantly rotating and never get locked into place. This is a good assumption, but at some point molecules do get locked into place. The energy of a Keesom interaction depends on the inverse sixth power of the distance, unlike the interaction energy of two spatially fixed dipoles, which depends on the inverse third power of the distance. The Keesom interaction can only occur among molecules that possess permanent dipole moments, i.e., two polar molecules. Also Keesom interactions are very weak van der Waals interactions and do not occur in aqueous solutions that contain electrolytes. The angle averaged interaction is given by the following equation: :$\frac = V,$ where ''m'' = dipole moment, $\varepsilon_0$ = permitivity of free space, $\varepsilon_r$ = dielectric constant of surrounding material, ''T'' = temperature, $k_\text$ = Boltzmann constant, and ''r'' = distance between molecules.

## Debye (permanent–induced dipoles) force

The second contribution is the induction (also termed polarization) or Debye force, arising from interactions between rotating permanent dipoles and from the polarizability of atoms and molecules (induced dipoles). These induced dipoles occur when one molecule with a permanent dipole repels another molecule's electrons. A molecule with permanent dipole can induce a dipole in a similar neighboring molecule and cause mutual attraction. Debye forces cannot occur between atoms. The forces between induced and permanent dipoles are not as temperature dependent as Keesom interactions because the induced dipole is free to shift and rotate around the polar molecule. The Debye induction effects and Keesom orientation effects are termed polar interactions. The induced dipole forces appear from the induction (also termed
polarization Polarization or polarisation may refer to: In the physical sciences *Polarization (waves), the ability of waves to oscillate in more than one direction, in particular polarization of light, responsible for example for the glare-reducing effect of ...
), which is the attractive interaction between a permanent multipole on one molecule with an induced (by the former di/multi-pole) 31 on another. This interaction is called the ''Debye force'', named after Peter J. W. Debye. One example of an induction interaction between permanent dipole and induced dipole is the interaction between HCl and Ar. In this system, Ar experiences a dipole as its electrons are attracted (to the H side of HCl) or repelled (from the Cl side) by HCl. The angle averaged interaction is given by the following equation: :$\frac = V,$ where $\alpha$ = polarizability. This kind of interaction can be expected between any polar molecule and non-polar/symmetrical molecule. The induction-interaction force is far weaker than dipole–dipole interaction, but stronger than the
London dispersion force London dispersion forces (LDF, also known as dispersion forces, London forces, instantaneous dipole–induced dipole forces, Fluctuating Induced Dipole Bonds or loosely as van der Waals forces) are a type of force acting between atom An atom ...
.

## London dispersion force (fluctuating dipole–induced dipole interaction)

The third and dominant contribution is the dispersion or London force (fluctuating dipole–induced dipole), which arises due to the non-zero instantaneous dipole moments of all atoms and molecules. Such polarization can be induced either by a polar molecule or by the repulsion of negatively charged electron clouds in non-polar molecules. Thus, London interactions are caused by random fluctuations of electron density in an electron cloud. An atom with a large number of electrons will have a greater associated London force than an atom with fewer electrons. The dispersion (London) force is the most important component because all materials are polarizable, whereas Keesom and Debye forces require permanent dipoles. The London interaction is universal and is present in atom-atom interactions as well. For various reasons, London interactions (dispersion) have been considered relevant for interactions between macroscopic bodies in condensed systems. Hamaker developed the theory of van der Waals between macroscopic bodies in 1937 and showed that the additivity of these interactions renders them considerably more long-range.

# Relative strength of forces

This comparison is approximate. The actual relative strengths will vary depending on the molecules involved.
Ionic bonding Ionic bonding is a type of chemical bond A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the Coulomb's law, electrostatic force of attraction be ...

and
covalent bond A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they s ...
ing will always be stronger than intermolecular forces in any given substance.

# Effect on the behavior of gases

Intermolecular forces are repulsive at short distances and attractive at long distances (see the
Lennard-Jones potential The Lennard-Jones potential (also termed the LJ potential or 12-6 potential) is an intermolecular pair potential. Among the Interatomic potential, intermolecular potentials, the Lennard-Jones potential is the potential that has been studied most e ...
). In a gas, the repulsive force chiefly has the effect of keeping two molecules from occupying the same volume. This gives a
real gas Real gases are nonideal gases whose molecules occupy space and have interactions; consequently, they do not adhere to the ideal gas law. To understand the behaviour of real gases, the following must be taken into account: * compressibility effects; ...
a tendency to occupy a larger volume than an
ideal gas An ideal gas is a theoretical gas Gas is one of the four fundamental states of matter In physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion ...
at the same temperature and pressure. The attractive force draws molecules closer together and gives a real gas a tendency to occupy a smaller volume than an ideal gas. Which interaction is more important depends on temperature and pressure (see
compressibility factor In thermodynamics Thermodynamics is a branch of physics that deals with heat, Work (thermodynamics), work, and temperature, and their relation to energy, radiation, and physical properties of matter. The behavior of these quantities is governe ...
). In a gas, the distances between molecules are generally large, so intermolecular forces have only a small effect. The attractive force is not overcome by the repulsive force, but by the
thermal energy Thermal radiation in visible light can be seen on this hot metalwork. Thermal energy refers to several distinct physical concepts, such as the internal energy of a system; heat or sensible heat, which are defined as types of energy transfer (as is ...
of the molecules.
Temperature Temperature ( ) is a physical quantity that expresses hot and cold. It is the manifestation of thermal energy Thermal radiation in visible light can be seen on this hot metalwork. Thermal energy refers to several distinct physical concept ...

is the measure of thermal energy, so increasing temperature reduces the influence of the attractive force. In contrast, the influence of the repulsive force is essentially unaffected by temperature. When a gas is compressed to increase its density, the influence of the attractive force increases. If the gas is made sufficiently dense, the attractions can become large enough to overcome the tendency of thermal motion to cause the molecules to disperse. Then the gas can condense to form a solid or liquid, i.e., a condensed phase. Lower temperature favors the formation of a condensed phase. In a condensed phase, there is very nearly a balance between the attractive and repulsive forces.

# Quantum mechanical theories

Intermolecular forces observed between atoms and molecules can be described phenomenologically as occurring between permanent and instantaneous dipoles, as outlined above. Alternatively, one may seek a fundamental, unifying theory that is able to explain the various types of interactions such as hydrogen bonding, van der Waals forces and dipole–dipole interactions. Typically, this is done by applying the ideas of
quantum mechanics Quantum mechanics is a fundamental theory A theory is a reason, rational type of abstraction, abstract thinking about a phenomenon, or the results of such thinking. The process of contemplative and rational thinking is often associated with ...
to molecules, and Rayleigh–Schrödinger
perturbation theory In mathematics Mathematics (from Greek: ) includes the study of such topics as numbers ( and ), formulas and related structures (), shapes and spaces in which they are contained (), and quantities and their changes ( and ). There is no g ...
has been especially effective in this regard. When applied to existing
quantum chemistry Quantum chemistry, also called molecular quantum mechanics, is a branch of chemistry Chemistry is the scientific discipline involved with Chemical element, elements and chemical compound, compounds composed of atoms, molecules and ions: thei ...
methods, such a quantum mechanical explanation of intermolecular interactions provides an array of approximate methods that can be used to analyze intermolecular interactions. One of the most helpful methods to visualize this kind of intermolecular interactions, that we can find in quantum chemistry, is the non-covalent interaction index, which is based on the electron density of the system. London dispersion forces play a big role with this.

# See also

*
Ionic bonding Ionic bonding is a type of chemical bond A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the Coulomb's law, electrostatic force of attraction be ...

* Salt bridges * Coomber's relationship *
Force field (chemistry) In the context of chemistry and molecular modelling, a force field is a computational chemistry, computational method that is used to estimate the forces between atoms within molecules and also between molecules. More precisely, the force field ...
*
Hydrophobic effect thumbnail, 250px, A droplet of water forms a spherical shape, minimizing contact with the hydrophobic leaf. The hydrophobic effect is the observed tendency of nonpolar substances to aggregate in an aqueous solution An aqueous solution is a sol ...
*
Intramolecular force An intramolecular force (or primary forces) is any force In physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion and behavior through Spacetime, sp ...
* Molecular solid *
Polymer A polymer (; Greek ''poly- Poly, from the Greek :wikt:πολύς, πολύς meaning "many" or "much", may refer to: Businesses * China Poly Group Corporation, a Chinese business group, and its subsidiaries: ** Poly Property, a Hong Kong inc ...

*
Quantum chemistry computer programs Quantum chemistry computer programs are used in computational chemistry to implement the methods of quantum chemistry. Most include the Hartree–Fock (HF) and some post-Hartree–Fock methods. They may also include density functional theory (DFT) ...
*
van der Waals force Microfiber cloth makes use of London-dispersion force to remove dirt without scratches. In molecular physics Molecular physics is the study of the physical properties of molecule File:Pentacene on Ni(111) STM.jpg, A scanning tunneling micr ...
*
Comparison of software for molecular mechanics modelingThis is a list of computer programs that are predominantly used for molecular mechanics calculations. See also * Car–Parrinello molecular dynamics * Comparison of force field implementations * Comparison of nucleic acid simulation software ...
*
Non-covalent interactionsA non-covalent interaction differs from a covalent bond in that it does not involve the sharing of electrons, but rather involves more dispersed variations of electromagnetic interactions between molecules or within a molecule. The chemical energy re ...
*
Solvation Solvation (or dissolution) describes the interaction of solvent A solvent (from the Latin language, Latin ''wikt:solvo#Latin, solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usual ...

# References

{{DEFAULTSORT:Intermolecular Force Intermolecular forces Chemical bonding Johannes Diderik van der Waals