This page gathers the 217 dictionary entries of which at least one sense is labelled “Physical” by Wiktionary. The definition shown is that sense; each word leads to its full entry. Page 1 of 2: from “Abel test” to “cloud point”.
- Abel test noun A test to determine the flash point of a volatile oil.
- absorbent noun A liquid used in the process of separating gases or volatile liquids, in oil refining.
- absorption noun the imbibing or reception by molecular or chemical action, of radiant energy; the process of being neutrons being absorbed by the nucleus…
- accommodation noun The act of fitting or adapting, or the state of being fitted or adapted; adaptation; adjustment.
- acidic adj Having a pH less than 7, or being sour, or having the strength to neutralize alkalis, or turning a litmus paper red.
- activated complex noun A transitional structure, in an energetically excited state, that forms between the reactants of a chemical reaction and breaks down to…
- activation analysis noun Any of several similar radiochemical techniques of analysis in which a subatomic particle or gamma ray is captured by a nuclide to form a…
- activation energy noun The energy required to initiate a reaction. For example, the flame from the fuse of a firecracker provides a small initial amount of…
- activator noun Something that activates a catalyst
- acyclic adj Not cyclic; having an open chain structure.
- advection noun The horizontal movement of a body of atmosphere (or other fluid) along with a concurrent transport of its temperature, humidity etc.
- air bath noun A sealed system containing air with a controlled temperature.
- alcogel noun A colloid where the dispersive media is alcohol.
- amount of substance noun The number of particles or formula units (depending on type) present of some substance in some sample; SI unit: mole.
- amperometry noun An analytical technique that involves the continuous measurement of electric current during a reaction or titration.
- analysis noun The process of breaking down a substance into its constituent parts, or the result of this process.
- anentropy noun A measure of the purity or chemical affinity in a thermodynamic system.
- anhydrous adj Having no water of crystallization.
- anionic detergent noun Any detergent in which the lipophilic part of the molecule is an anion; examples include soaps and synthetic long-chain sulfates and…
- anisotopic adj Having only one isotope
- antarafacial adj Of a chemical reaction, involving two simultaneous changes in bonding to opposite faces of a common centre (or related centres) of a…
- anti adj That has a torsion angle between 90° and 180°
- anti-bumping granule noun A small, coarse stone added to boiling liquids to make them boil more evenly, without sudden, violent releases of vapour; used especially…
- antibonding orbital noun an atomic or molecular orbital whose energy increases as its constituent atoms are brought closer together - thus generating a repulsive…
- anticlinal adj Describing a torsion angle between 90° and 150°.
- apolar adj Having no dipole
- aqueous adj Consisting mostly of water. Often used in the expression "aqueous solution".
- Arrhenius equation noun An equation which approximates the dependence of the rate of any chemical reaction on the temperature.
- ataxia noun The condition of a polymer in which the orientation of the subunits is random
- athermic adj involving no enthalpy exchange
- atomic orbital noun A mathematical function that describes the wave-like behavior of either one electron or a pair of electrons in an atom. This function can…
- atropisomer noun Any conformer that can be isolated as a separate chemical compound and that arises from restricted rotation about a single bond, as in…
- attack verb (Of a chemical species) To approach a chemical species or bond in order to form a bond with it.
- attomolar adj Describing a concentration of 10⁻¹⁸ mole per litre. This is only about 600 particles per cubic centimeter.
- autophobic adj Exhibiting autophobicity
- autophobicity noun The formation of droplets at the boundary of a two-phase system
- axial adj Oriented parallel to the axis running through the centre of a cyclohexane ring, as opposed to equatorial. See Axial bond.
- backdonation noun The transfer of one or more electrons from an atomic orbital of an atom to an antibonding orbital of a ligand.
- ball and stick noun The representation of chemical substances in a three-dimensional way using ball-and-stick models.
- ball-and-stick model noun A molecular model of a chemical substance, displaying the three-dimensional position of the atoms (as spheres) and the bonds between them…
- barrierless adj Not requiring activation energy.
- bead noun A glassy drop of molten flux, as borax or microcosmic salt, used as a solvent and color test for several mineral earths and oxides, as of…
- bicapped adj Having the shape of such a prism
- bicyclic noun A bicyclic compound.
- bidentate adj Of a ligand, forming two separate chemical bonds to a coordinating metal ion.
- bivalent adj Having a valence of 2; having two ligands
- boat noun One of two possible conformations of cyclohexane rings (the other being chair), shaped roughly like a boat.
- Bohr radius noun A physical constant, the approximate distance between the proton and electron of a hydrogen atom in its ground state, equal to about 53…
- boiling point noun The temperature at which a liquid boils, with the vapor pressure equal to the given external pressure.
- boiling-point elevation noun The phenomenon that the boiling point of a liquid (a solvent) will be higher when another compound is added.
- bond dissociation energy noun The change in enthalpy that occurs when a specific chemical bond is broken; a measure of the strength of the bond
- bond distortion noun Any change in the lengths of chemical bonds, and in the angles between them, caused by steric hindrance and similar forces
- bond energy noun The sum of the bond dissociation energies of all the bonds in a molecule
- bonding orbital noun A molecular orbital, responsible for a covalent bond between two atoms, formed by overlap of their corresponding atomic orbitals
- Born-Haber cycle noun A cycle concerned with the formation of an ionic compound from the reaction of a metal (often a Group I or Group II element) with a halogen…
- bridge noun An intramolecular valence bond, atom or chain of atoms that connects two different parts of a molecule; the atoms so connected being…
- bridgehead noun Either of the two atoms in different parts of a molecule that are connected by a bridge of two or more other atoms
- bump verb To suddenly boil, causing movement of the vessel and loss of liquid.
- bumping noun The violent boiling when a homogeneous liquid is superheated to the point that the bubbles are formed at pressure greater than atmospheric…
- Bunsen coefficient noun The number of milliliters of gas dissolved in a milliliter of liquid at atmospheric pressure and a specified temperature.
- calcine verb To heat (a substance) without melting in order to drive off water, etc., and to oxidize or reduce it; specifically, to decompose…
- calomel electrode noun A reference electrode or half-cell consisting of mercury, mercurous chloride and potassium chloride; used in pH meters and voltmeters.
- calorie noun A non-SI unit of energy, equivalent to 4.184 joules, that can raise the temperature of a gram of water by one degree Celsius. This unit was…
- canonical form noun Any of a set of representations of the resonance structure of a molecule each of which contributes to the real structure; a contributing…
- carbonatation noun A chemical reaction in which calcium hydroxide reacts with carbon dioxide to form insoluble calcium carbonate.
- carbonation noun The state of having carbon dioxide gas dissolved in a liquid; the act or process of creating that state.
- carbonific adj Decomposing to create a greater volume of carbon than the volume of the original material
- carbonometer noun An early device for measuring the concentration of carbon dioxide in a gas, by bubbling it through limewater and measuring the cloudiness.
- carcerand noun Any of a class of complex polycyclic compounds, based on calixarenes, that form a sphere within which a guest molecule may be held.
- cast verb To throw.
- cation-π noun A noncovalent interaction between a cation, a positive ion like Li⁺ or Na⁺, and an aromatic residue such as benzene, ethylene, acetylene.
- cationic detergent noun Any detergent in which the lipophilic part of the molecule is a cation; examples include long-chain quaternary ammonium compounds
- cationically adv In a cationic manner
- CD noun Initialism of circular dichroism.
- chain noun A number of atoms in a series, which combine to form a molecule.
- chain reaction noun A chemical reaction where the products of the reaction influence the reactants of a following reaction, leading to positive feedback.
- chair noun One of two possible conformers of cyclohexane rings (the other being boat), shaped roughly like a chair.
- chalcophile noun In the Goldschmidt classification, an element such as copper that forms sulfide minerals if enough sulfur is available.
- chaotropic adj That disrupts hydrogen bonds, especially within or between biological molecules.
- charged particle noun An ion.
- chemical equilibrium noun The state of a reversible reaction in which the rates of the forward and reverse reactions are the same
- chemical kinetics noun The study of the rates of chemical reactions, especially as a means of elucidating reaction pathways or mechanisms.
- chemical structure noun The arrangement of chemical bonds between atoms in a molecule (or in an ion or radical with multiple atoms), specifically which atoms are…
- chemiexcitation noun The generation of an electronically excited molecule by a chemical reaction of reactants in their ground state
- chemiosmosis noun Any chemical reaction that occurs through an intervening semipermeable membrane, especially through a membrane in a biological cell
- chemisorption noun the process in which a substance is adsorbed on the surface of another by means of chemical rather than physical bonding
- chemobiology noun The study of the effect of chemical structure on biological activity
- chemodynamics noun The study of the dynamics of chemical reactions
- chemomechanics noun An area of the physical chemistry of polymers concerned with the reversible conversion of chemical energy into mechanical energy.
- chiral adj that exhibits chirality; as in the left-handed and right-handed versions of a helix, or a molecule with L- and D- stereoisomers.
- chromatotron noun A device used in radial chromatography in which solvent is added to the center of a covered silica layered plate which spins to drive a…
- chronopotentiometry noun A form of electroanalysis in which the rate of change of potential at an electrode is measured at constant current
- chyometer noun An instrument for measuring the specific gravity of liquids, consisting of a tube with a piston inside.
- cis adj In (or constituting, forming, or describing) a double bond in which the greater radical on both ends is on the same side of the bond.
- cis- prefix Forms names of chemical compounds in which two atoms or groups are situated on the same side of some plane of symmetry passing through the…
- cis-trans isomerism noun A form of isomerism in which, in one isomer two atoms or groups are on the same side of the plane of a double bond or ring, whereas in the…
- clinal adj Describing a torsion angle between 30° and 150°
- close verb To move a thing, or part of a thing, nearer to another so that the gap or opening between the two is removed.
- closed system noun A physical system whose interaction with its environment is limited to particular types of transfer, so that certain quantities are…
- cloud point noun The temperature at which one component of a mixture of liquids begins to solidify (or a mixture of liquids starts to become immiscible) on…