Chemistry terminology · MLC-0109

Chemistry terms: R (726)

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• R diadA sequence of two adjacent monomer units in a polymer chain where the substituents on the main chain carbons...
• R, SA system of stereodescriptors used to denote the absolute configuration of a chiral center in a molecule. The...
• r2A statistical measure, also known as the coefficient of determination, that indicates the proportion of the...
• RabbitA pneumatic transfer system used to rapidly transport samples into and out of an irradiation position, such...
• RacemateAn equimolar mixture of a pair of enantiomers, which are stereoisomers that are non-superimposable mirror...
• RacemicDescribing a mixture that contains equal amounts of a pair of enantiomers. A racemic mixture is optically...
• Racemic compoundA crystalline solid formed from an equimolar mixture of two enantiomers that crystallize together as a...
• Racemic conglomerateA mechanical mixture of crystals, each of which contains only one enantiomer. This solid phase forms when a...
• Racemic mixtureA mixture containing equal quantities of two enantiomers of a chiral compound. Unlike a racemic compound, the...
• Racemic packingThe arrangement of enantiomeric molecules in a crystal lattice where both mirror-image forms are present in...
• RacemizationThe process by which a pure enantiomer or an enantiomerically enriched mixture is converted into a racemate...
• RachischisisA severe congenital malformation characterized by a complete or nearly complete failure of the neural tube to...
• RadA non-SI unit of absorbed dose of ionizing radiation, representing the energy deposited per unit mass of...
• Radial arm mazeAn experimental apparatus used in behavioral neuroscience to assess spatial learning and memory in rodents...
• Radial ejectionThe process of expelling ions from an ion trap in a direction perpendicular to the central axis of the trap...
• Radial electrostatic field analyserA device that separates charged particles based on their kinetic energy by deflecting them through a curved...
• Radial elutionA mode of chromatography where the mobile phase flows outwards from the center of a circular chromatographic...
• Radial immunodiffusionA quantitative immunological technique used to measure the concentration of an antigen or antibody in a...
• Radial sectioningA sample preparation technique for surface analysis where a spherical crater is created on the sample...
• Radial viewing modeAn observation configuration in inductively coupled plasma optical emission spectroscopy (ICP-OES) where the...
• RadianA unit of angular measure, representing the ratio of the arc length to the radius of a circle. One radian is...
• RadianceThe radiant power originating from, passing through, or received by a surface, measured per unit of solid...
• Radiant doseThe total energy of ionizing radiation absorbed per unit mass of a specified material. It quantifies the...
• Radiant energyEnergy transmitted in the form of electromagnetic waves or photons. This energy encompasses the entire...
• Radiant energy densityThe radiant energy contained within a unit volume of space. This quantity describes the concentration of...
• Radiant exitanceThe radiant power emitted by a source, divided by the area of the emitting surface. It quantifies the total...
• Radiant exposureThe total radiant energy incident on a surface per unit area, calculated by integrating the irradiance over...
• Radiant intensityThe radiant power emitted by a point source per unit solid angle in a specific direction. It describes the...
• Radiant powerThe total energy radiated, transmitted, or received per unit time, also known as radiant flux. It quantifies...
• Radiant quantitiesA set of physical properties used to describe electromagnetic radiation, based on the total energy...
• RadiationThe process by which energy propagates through space or a material medium, either as electromagnetic waves or...
• Radiation adsorptionThe process where electromagnetic radiation, such as ultraviolet light or X-rays, is absorbed by a material...
• Radiation catalysisA chemical process where the rate of a reaction is enhanced by the absorption of ionizing radiation, such as...
• Radiation catalystA substance that, when exposed to ionizing radiation, facilitates or accelerates a chemical reaction without...
• Radiation chemistryA branch of chemistry that investigates the chemical effects of high-energy radiation on matter. This field...
• Radiation constantsPhysical constants that appear in equations describing the properties of electromagnetic radiation...
• Radiation continuumA continuous distribution of electromagnetic radiation emitted or absorbed over a broad range of wavelengths...
• Radiation counterAn instrument designed to detect and quantify ionizing radiation by converting the energy of incident...
• Radiation dampingThe loss of energy from a precessing nuclear magnetization to the surrounding environment through the...
• Radiation desorptionThe removal of adsorbed species from a surface due to the impact of incident radiation, such as photons or...
• Radiation detectorA device that indicates the presence of ionizing radiation and often measures its intensity or energy. It...
• Radiation filterA material or device that selectively transmits or attenuates certain wavelengths or energies of radiation...
• Radiation hazardThe potential for harm to living organisms or the environment resulting from exposure to ionizing radiation...
• Radiation reactionA chemical transformation induced in a polymer by exposure to high-energy radiation, such as gamma rays...
• Radiation sensitisationThe process by which a substance, known as a radiation sensitiser, increases the susceptibility of a chemical...
• Radiation sensitiserA chemical compound that increases the sensitivity of a system to the effects of ionizing radiation. This...
• Radiation spectrumA distribution of the intensity of radiation as a function of its energy, wavelength, or frequency. This...
• Radiation thermal catalysisA catalytic process that combines the effects of both radiation and heat to accelerate a chemical reaction...
• Radiation toxicologyThe scientific discipline that studies the adverse effects of ionizing and non-ionizing radiation on living...
• Radiation trappingThe re-absorption of emitted photons by other atoms or molecules within the same medium before they can...
• Radiation-activationThe process of initiating or enhancing the activity of a material or catalyst through exposure to radiation...
• Radiation-chemical yieldThe number of molecules of a specific product formed or reactant consumed per 100 eV of energy absorbed from...
• Radiation-generated catalysisA catalytic process where the active species or catalytic sites are produced or activated directly by the...
• Radiation-induced adsorptionThe process where the adsorption of molecules onto a surface is promoted or enhanced by exposure to...
• Radiationless deactivationThe process by which an excited electronic state of an atom or molecule loses its excitation energy without...
• Radiationless transitionA process in which an excited electronic state of an atom or molecule decays to a lower energy state without...
• Radiation-stimulated diffusionThe enhanced movement of atoms or molecules within a material, driven by the energy imparted by incident...
• Radiative absorptionThe process by which an atom, molecule, or ion absorbs a photon of electromagnetic radiation, leading to a...
• Radiative captureA nuclear reaction in which an atomic nucleus absorbs an incident particle, such as a neutron or proton, and...
• Radiative charge carrier recombinationThe process where an electron and a hole recombine, releasing their energy as a photon of light. This...
• Radiative de-excitationThe process by which an excited atom, molecule, or nucleus returns to a lower energy state by emitting a...
• Radiative energy transferThe process by which energy is transferred from an excited donor molecule to an acceptor molecule through the...
• Radiative lifetimeThe reciprocal of the sum of the unimolecular rate constants for all radiative transitions from a given...
• Radiative transfer equationA mathematical expression that describes the propagation of radiant energy through a medium, accounting for...
• Radiative transitionA process in which an atom, molecule, or ion changes its energy state by absorbing or emitting a photon. This...
• RadicalA molecular entity, such as an atom or molecule, that possesses one or more unpaired valence electrons. This...
• Radical centreThe specific atom within a polyatomic radical upon which the unpaired electron is predominantly localized...
• Radical copolymerizationA type of copolymerization reaction initiated by free radicals, where two or more different monomers are...
• Radical entryThe process by which a free radical, typically originating from an initiator, enters a polymer particle or...
• Radical entry frequencyThe average number of free radicals entering a single polymer particle per unit time in a dispersed...
• Radical exitThe process by which a radical, typically a small initiator radical or a short oligomeric radical, diffuses...
• Radical exit frequencyThe average number of free radicals leaving a single polymer particle per unit time in a dispersed...
• Radical ionA molecular entity that possesses both an unpaired electron and a net electrical charge. These species...
• Radical pairA molecular entity comprising two radicals in close proximity, held together within a solvent cage or as part...
• Radical photosubstitutionA photochemical reaction in which a substituent on a molecule is replaced by another group through a...
• Radical polymerizationA type of chain polymerization in which the kinetic chain carriers are free radicals. The process involves...
• Radical reactivity scaleA quantitative ranking of the reactivity of different radicals toward a specific reference reaction or...
• Radical ring-opening polymerizationA type of chain polymerization where a cyclic monomer undergoes ring-opening initiated by a free radical...
• RadiculitisInflammation of a nerve root, which can cause pain, numbness, tingling, or weakness in the area supplied by...
• RadioactiveDescribing an unstable atomic nucleus that undergoes spontaneous disintegration, emitting radiation in the...
• Radioactive ageThe time elapsed since the formation of a material, determined by measuring the relative abundances of a...
• Radioactive contaminationThe undesirable presence of radioactive substances on surfaces, within materials, or in the environment...
• Radioactive coolingThe decrease in the radioactivity of a sample over time due to the decay of its constituent radionuclides. As...
• Radioactive datingA method for determining the age of an object or material by measuring the relative abundance of a...
• Radioactive decayThe spontaneous process by which an unstable atomic nucleus transforms into a more stable nucleus by emitting...
• Radioactive equilibriumA condition in a radioactive decay series where the rate of formation of a daughter nuclide equals its rate...
• Radioactive falloutRadioactive particles that are carried into the atmosphere following a nuclear explosion or reactor accident...
• Radioactive sourceA quantity of radioactive material specifically prepared and encapsulated for its radiation to be used for a...
• Radioactive steady stateA condition in a system where the rate of production of a radionuclide equals its rate of decay, resulting in...
• Radioactive tracerA radioactive isotope incorporated into a substance to track its movement or distribution within a system...
• Radioactive tracer techniqueAn analytical method that uses radioactive isotopes to follow the path of a substance through a complex...
• Radioactive wasteAny waste material that contains radioactive substances in concentrations exceeding regulatory clearance...
• RadioactivityThe spontaneous emission of radiation from the unstable nuclei of certain atoms, resulting in their...
• Radioallergosorbent testAn in vitro diagnostic test used to detect and quantify specific immunoglobulin E (IgE) antibodies in a...
• Radiochemical activation analysisA method of activation analysis where chemical separations are performed after irradiation to isolate the...
• Radiochemical purificationThe process of separating a specific radionuclide or radioactive compound from other radioactive or...
• Radiochemical purityThe fraction of the total radioactivity in a sample that is present in the stated chemical form of the...
• Radiochemical separationA chemical process used to isolate and purify specific radionuclides from a mixture, often involving...
• Radiochemical yieldThe fraction or percentage of a specific radionuclide initially present in a sample that is recovered after a...
• RadiochemistryThe branch of chemistry concerned with radioactive materials, including the study of their nuclear...
• RadiochromatographAn instrument that combines chromatographic separation with a radiation detector to analyze radioactive...
• RadiocolloidA colloidal particle that contains radioactive atoms. These particles can form when a radioactive substance...
• Radioenzymatic assayAn analytical method that uses a radioactive substrate or cofactor in an enzyme-catalyzed reaction to...
• RadiofrequencyA range of frequencies of electromagnetic radiation between the upper end of the audio range and the lower...
• Radiofrequency coilA device in a nuclear magnetic resonance spectrometer that generates an oscillating magnetic field and...
• Radiofrequency generatorAn electronic device that produces alternating current at radiofrequencies. In analytical chemistry, it is a...
• Radiofrequency glow discharge optical emission spectroscopyA spectroscopic technique that uses a radiofrequency glow discharge as an atomization and excitation source...
• RadiographA photographic image produced by the passage of ionizing radiation, such as X-rays or gamma rays, through an...
• Radiogravimetric analysisA quantitative analytical method where the amount of a substance is determined by measuring the activity of a...
• RadioimmunoassayA highly sensitive immunoassay technique that measures the concentration of a substance, typically an...
• RadioimmunoconjugateA molecule formed by chemically linking a radionuclide (radioisotope) to an antibody or antibody fragment...
• RadioiodinationThe chemical process of introducing a radioactive isotope of iodine, such as iodine-125 or iodine-131, into a...
• RadioisotopeAn atom that possesses an unstable nucleus and undergoes radioactive decay, emitting radiation in the...
• Radioisotope dilution analysisAn analytical method for determining the amount of a substance in a sample by adding a known quantity of its...
• Radioisotope induced X-ray emission analysisAn analytical technique that uses X-rays emitted from a radioisotope source to excite characteristic X-rays...
• RadioligandA molecule that is labeled with a radioactive isotope and binds specifically to a receptor, enzyme, or other...
• RadioluminescenceThe emission of light from a substance as a direct result of its excitation by ionizing radiation. This...
• RadiolysisThe chemical decomposition of a substance induced by exposure to high-energy radiation, such as X-rays, gamma...
• Radiometric analysisA quantitative analytical method that determines the amount of a substance by measuring the activity of a...
• Radiometric titrationA titration method where the endpoint is determined by monitoring the change in radioactivity of the solution...
• RadiometryThe measurement of electromagnetic radiation, including visible light, infrared, and ultraviolet radiation...
• RadionuclideAn atom characterized by an unstable nucleus that undergoes radioactive decay, emitting radiation in the...
• Radionuclidic purityA measure of the proportion of a sample's total radioactivity that is due to the desired radionuclide. It is...
• Radioreceptor assayA biochemical assay that measures the concentration of a substance by its ability to compete with a...
• Radiorelease analysisA quantitative analytical method where the analyte reacts with a reagent containing a radioactive component...
• Radius of gyrationA measure of the average size of a polymer coil in solution or in the melt, representing the root-mean-square...
• RaffinateThe phase remaining after a desired component has been selectively extracted from it in a liquid-liquid...
• Rain outThe process by which atmospheric aerosols and soluble gases are removed from the atmosphere by being...
• Raman bandA peak or feature observed in a Raman spectrum, corresponding to a specific vibrational mode of a molecule...
• Raman optical activityA spectroscopic technique that measures the difference in Raman scattering intensity for right and left...
• Raman scatteringThe inelastic scattering of electromagnetic radiation by molecules, resulting in a change in the energy and...
• Raman shiftThe difference in wavenumber between the incident monochromatic radiation and the scattered Raman radiation...
• Raman spectroscopyA spectroscopic technique used to observe vibrational, rotational, and other low-frequency modes in a system...
• Raman spectrumA plot of the intensity of Raman scattered light as a function of the Raman shift, which is the difference in...
• Raman wavenumber shiftThe difference in wavenumber between the incident monochromatic radiation and the scattered Raman radiation...
• Randles-Ševčík equationsA set of mathematical relationships that describe the current-voltage response in cyclic voltammetry for a...
• Random coilA polymer conformation characterized by a highly flexible and disordered arrangement of its chain segments...
• Random coincidenceThe simultaneous detection of two or more unrelated events by a coincidence counting system, occurring purely...
• Random copolymerA copolymer in which the different types of monomer units are distributed in a statistically random sequence...
• Random copolymerizationA copolymerization process that results in a random copolymer, where the different monomer units are...
• Random errorA component of measurement error that varies unpredictably in magnitude and direction when a measurement is...
• Random forest methodA machine learning technique that constructs multiple decision trees during training and outputs the mode of...
• Random sampleA portion of material taken from a larger quantity in such a way that every part of the original material has...
• Random samplingA procedure for selecting a subset of items from a larger population or lot where each item has an equal and...
• RangeThe difference between the highest and lowest values in a set of measurements or observations. It provides a...
• Range of measurementThe set of values of a quantity for which a measuring instrument or method is designed to provide accurate...
• Range stragglingThe statistical variation in the penetration depth of energetic ions or particles into a material, even when...
• Raoult’s lawA principle stating that the partial vapor pressure of each component in an ideal mixture of liquids is equal...
• Rapid-scan Fourier-transform infrared spectroscopyA spectroscopic technique that acquires a complete interferogram, representing the infrared absorption...
• Rare-earth-metal-mediated coordination-addition polymerizationA polymerization process where rare-earth metal complexes act as catalysts to facilitate the coordination and...
• RasterA systematic pattern of scanning a surface or area with a probe or beam, typically in a series of parallel...
• Raster scanA method of generating an image or pattern by systematically scanning a beam, such as an electron beam or...
• RateThe change in the value of a quantity per unit of time. This fundamental concept describes how quickly a...
• Rate constant-based modelA mathematical framework that describes the kinetics of chemical or biological processes using rate constants...
• Rate differenceThe absolute difference between two rates, typically incidence rates or mortality rates, in two distinct...
• Rate lawAn equation that expresses the rate of a chemical reaction as a function of the concentrations of the...
• Rate of change of a quantityThe derivative of a quantity with respect to time, indicating how rapidly the quantity's value is increasing...
• Rate of change ratioThe ratio of the rate of change of one quantity to the rate of change of another related quantity. This...
• Rate of conversionThe rate at which the extent of a chemical reaction changes with respect to time, often expressed in moles...
• Rate of flow of liquid metal in polarographyThe mass of mercury flowing per unit time from the capillary of a dropping mercury electrode. This parameter...
• Rate of fluid consumptionThe volume of a liquid sample that is aspirated and consumed by a device per unit of time. In analytical...
• Rate of formationThe rate at which a product appears in a chemical reaction, expressed as the positive change in its...
• Rate of generationThe amount of substance of a specific chemical species formed per unit of time within a defined volume of a...
• Rate of liquid consumptionThe volume of sample solution that is drawn into the nebulizer and atomizer of an atomic spectrometer per...
• Rate of migrationThe speed at which a charged particle or molecule moves through a medium under the influence of an electric...
• Rate of nucleationThe number of new stable nuclei or particles formed per unit volume per unit time in a phase transition, such...
• Rate of polymerisationThe speed at which monomer units are converted into polymer chains in a polymerization reaction. It is...
• Rate of reactionThe change in the concentration of a reactant or product per unit time, adjusted for the stoichiometric...
• Rate of surface recombinationThe speed at which photogenerated electron-hole pairs recombine non-radiatively at the surface of a...
• Rate ratioA measure of association that compares the incidence rate of an event in an exposed group to the incidence...
• Rate-controlling stepA step in a multi-step reaction mechanism that significantly influences the overall rate of the reaction...
• Rate-determining stepThe single elementary step in a reaction mechanism that has the highest activation energy and is therefore...
• RatemeterAn electronic instrument that measures and displays the average rate of discrete events, such as pulses from...
• Rate-of-living theory of agingA biological hypothesis proposing that an organism's lifespan is inversely proportional to its metabolic...
• RatioA quantitative relationship between two numbers or quantities, indicating how many times one value contains...
• RatticideA chemical substance specifically designed and used to kill rats and other rodents. These compounds typically...
• Raw cokeThe carbonaceous solid product obtained directly from the coking process of petroleum or coal, prior to any...
• Raw dataThe initial measurements or observations collected directly from an experiment or analytical instrument...
• Rayleigh limitThe theoretical maximum charge that a liquid droplet can sustain before becoming unstable and undergoing...
• Rayleigh ratioA measure of the intensity of light scattered by a sample at a specific angle, normalized by the incident...
• Rayleigh scatteringThe elastic scattering of electromagnetic radiation by particles that are much smaller in diameter than the...
• Raynaud phenomenonA condition characterized by episodic vasospasm of small arteries and arterioles, most frequently affecting...
• Rayon-based carbon fibresCarbon fibers produced by the pyrolysis of rayon, a regenerated cellulose fiber, as the precursor material...
• Re, SiStereochemical descriptors used to specify the faces of a trigonal planar atom in a chiral molecule...
• ReabsorptionThe process by which substances are transported from a fluid back into the blood. In toxicology and...
• ReactanceThe opposition to the flow of alternating current (AC) in an electrical circuit, arising from capacitance or...
• ReactantA chemical substance that undergoes transformation during a chemical reaction, leading to the formation of...
• Reacting bond rulesA set of qualitative principles used to predict the structure of transition states in organic reactions...
• Reaction barrierThe energy maximum along the minimum energy pathway connecting reactants to products in a chemical reaction...
• Reaction chromatographyA chromatographic technique where a chemical reaction occurs either before, during, or after the separation...
• Reaction coordinateA generalized geometric parameter that describes the progress of a chemical reaction from reactants to...
• Reaction cross-sectionA measure of the probability that a specific chemical reaction will occur when two particles collide. It...
• Reaction dynamicsThe study of the detailed motions of atoms and molecules during a chemical reaction, focusing on how energy...
• Reaction injection mouldingA manufacturing process where two or more low-viscosity liquid monomers or prepolymers are rapidly mixed and...
• Reaction pathThe trajectory followed by a chemical system as it transforms from reactants to products, typically...
• Reaction path degeneracyThe number of equivalent reaction paths that connect a reactant state to a product state through a transition...
• Reaction probabilityThe likelihood that a collision between reactant molecules will result in a chemical reaction. It is a...
• Reaction stageA conceptual division of a reaction mechanism that involves at least one reaction intermediate. It represents...
• Reaction stepAn elementary reaction that involves the formation or breaking of chemical bonds, occurring in a single...
• Reaction timeThe elapsed time from the initiation of a chemical reaction, typically by mixing reagents, to the point when...
• ReactiveDescribing a chemical species that readily undergoes chemical transformation due to its inherent instability...
• Reactive adsorptionThe process where a molecule adsorbs onto a surface and subsequently undergoes a chemical reaction while...
• Reactive airways dysfunction syndromeA non-allergic form of asthma that develops acutely after a single, high-level exposure to an irritant gas...
• Reactive astrocyteAn astrocyte that undergoes morphological, molecular, and functional changes in response to central nervous...
• Reactive blendingA process of mixing two or more polymers or polymer precursors in the molten state, where chemical reactions...
• Reactive complexA transient molecular entity formed during a chemical reaction, representing an unstable configuration of...
• Reactive desorption electrospray ionization mass spectrometryA variant of desorption electrospray ionization (DESI) mass spectrometry where a reagent is added to the...
• Reactive gliosisA complex process involving the proliferation, hypertrophy, and functional changes of glial cells, primarily...
• Reactive ion etchingA dry etching technique used in microfabrication that combines chemical reactions with physical sputtering to...
• Reactive nitrogen speciesA group of highly reactive molecules containing nitrogen that are derived from nitric oxide or its...
• Reactive oxygen speciesHighly reactive molecules containing oxygen, such as superoxide radicals (O₂⁻·), hydrogen peroxide (H₂O₂)...
• Reactive polymerA polymer that contains functional groups capable of undergoing further chemical reactions, either with other...
• Reactive polymer processingA method where the final shaping of a polymeric material and its chemical synthesis or modification occur...
• Reactive scatteringA technique used to study the dynamics of chemical reactions by observing the angular and velocity...
• Reactivity indexA theoretical parameter derived from quantum chemical calculations that quantifies the susceptibility of a...
• Reactivity-selectivity principleA postulate stating that a more reactive chemical reagent or intermediate is less selective in its reactions...
• ReadabilityThe smallest difference between two measured values that can be meaningfully distinguished on the display of...
• Readily biodegradableDescribing a substance that undergoes extensive and relatively rapid degradation by microorganisms under...
• ReadingThe value indicated by an analytical instrument or device at a specific point in time or under particular...
• Reagent gasA gas introduced into an ion source or ion trap of a mass spectrometer to produce reagent ions through...
• Reagent ionAn ion formed from a reagent gas that subsequently reacts with an analyte molecule or ion in a mass...
• ReaginAn antibody, primarily immunoglobulin E (IgE), that mediates immediate hypersensitivity reactions, such as...
• Real potential of a species in a phaseThe total energy required to bring a charged species from a vacuum to a specific phase, accounting for both...
• Real spectrumA spectrum where the imaginary part of the complex data is zero or negligible. This type of spectrum is often...
• Realised nicheThe actual set of environmental conditions and resources under which a species persists in the presence of...
• Real-time polymerase chain reactionA molecular biology technique that monitors the amplification of deoxyribonucleic acid (DNA) during the...
• RearingA specific motor behavior observed in laboratory animals, particularly rodents, characterized by standing...
• Rearrangement ionA fragment ion formed in a mass spectrometer that has undergone a structural reorganization of its atoms...
• Rearrangement stageA part of a reaction mechanism where atoms or groups within a molecule migrate to form a new structural...
• Reasonable maximum exposureA quantitative estimate of the highest exposure that is reasonably expected to occur for a given population...
• Reasonable worst caseA scenario used in risk assessment that represents a plausible, yet conservative, combination of conditions...
• ReboundThe exacerbation or recurrence of symptoms, often with increased intensity, after the cessation of a...
• Rebound headacheA chronic daily headache that develops or worsens due to the overuse of acute headache medications. This...
• Rebound reactionA type of chemical reaction, particularly in gas-phase kinetics, where a radical abstracts an atom from...
• RecalcitranceThe property of a substance, typically an organic compound, to resist degradation or breakdown by biological...
• RecallA metric for evaluating the performance of a classification model, such as those used in virtual screening...
• Recall antigenAn antigen to which an individual has previously been exposed and developed an immune response, leading to...
• Received radiant flux densityThe radiant flux incident on an infinitesimally small element of a surface, divided by the area of that...
• Receiver-operator characteristic curveA graphical plot that illustrates the diagnostic ability of a binary classifier system as its discrimination...
• Receiving waterA body of surface water, such as a river, lake, or ocean, into which wastewater, stormwater, or other...
• ReceptorA macromolecule, usually a protein, located on the cell surface or within the cytoplasm, that specifically...
• Receptor-mediated endocytosisA cellular process where specific molecules, or ligands, bind to receptors on the cell surface, triggering...
• RecessiveDescribing an allele whose phenotypic effect is expressed only in the homozygous state, when two identical...
• Recessive geneA gene that produces its characteristic effect only when its allele is inherited from both parents, resulting...
• Reciprocal mesenchymal-epithelial interactionA continuous, bidirectional signaling process between mesenchymal cells and adjacent epithelial cells that...
• Reciprocal salt systemA system composed of two salts with a common ion, or two pairs of salts that can exchange ions, resulting in...
• Reciprocal translocationA chromosomal abnormality resulting from the mutual exchange of segments between two different...
• Recognition siteA specific sequence of nucleotides on a DNA or RNA molecule, or a particular three-dimensional structure on a...
• RecoilThe momentum imparted to an atom or nucleus as a result of emitting a particle or photon. This phenomenon...
• Recoil labellingA method for introducing a radioactive nuclide into a molecule by exploiting the kinetic energy imparted to...
• Recoil-free fractionThe proportion of gamma-ray emission or absorption events in Mössbauer spectroscopy that occur without a...
• Recombinant antibodyAn antibody produced using genetic engineering techniques, where the genes encoding the antibody are cloned...
• Recombinant deoxyribonucleic acidA deoxyribonucleic acid (DNA) molecule formed by laboratory methods of genetic recombination to bring...
• RecombinationThe process by which two complementary strands of nucleic acid, such as DNA or RNA, re-associate to form a...
• Recombination centreA defect or impurity within a semiconductor material that facilitates the non-radiative recombination of...
• Recombination energyThe energy associated with the reorganization of molecular geometry and electronic structure that occurs...
• Recombination of photocarriersThe process by which photogenerated electron-hole pairs in a semiconductor material return to their...
• Recombination signal sequenceSpecific DNA sequences flanking the variable (V), diversity (D), and joining (J) gene segments in...
• Recommended exposure levelA guideline for occupational exposure to hazardous substances, established by regulatory bodies to protect...
• Recommended limitA guideline or maximum permissible concentration of a substance in an environmental medium or biological...
• Reconstituted waterWater prepared by adding specific salts and minerals to deionized or distilled water to achieve a desired...
• ReconstitutionThe process of restoring a substance, such as a dried powder or concentrate, to its original liquid or...
• Reconstructive transitionA type of phase transition in the solid state that involves the breaking of primary chemical bonds and the...
• Recovered quantity value ratioA measure of the efficiency of an analytical procedure, calculated as the ratio of the quantity value...
• RecoveryThe fraction of an analyte that is successfully extracted or detected from a sample matrix, expressed as a...
• Recovery timeThe duration required for a radiation detector or an electronic circuit to return to its normal operating...
• RecrystallizationA process of purification for solid compounds, involving dissolution in a hot solvent followed by cooling to...
• Rectilinear ion trapA type of ion trap mass analyzer that confines ions using radio frequency electric fields within a linear...
• RectumThe final section of the large intestine, which terminates at the anal canal. Its primary physiological...
• Recursive partitioningA statistical method used for building decision trees by repeatedly splitting a dataset into smaller, more...
• RecyclingThe collection and reprocessing of materials that would otherwise be disposed of as waste, transforming them...
• Red pulpA major component of the spleen, primarily involved in filtering blood, removing old or damaged red blood...
• Red shiftA shift of an absorption or emission band in a spectrum to longer wavelengths (lower energy). This phenomenon...
• RedepositionThe process where material that has been removed from a surface, typically by sputtering or etching...
• Redox dopingA process for modifying the electronic properties of a conjugated polymer by exposing it to an oxidizing or...
• Redox indicatorA substance that undergoes a distinct and reversible color change over a specific range of redox potentials...
• Redox ion exchangersPolymeric materials containing functional groups that can undergo reversible oxidation-reduction reactions...
• Redox mediationThe process where an intermediate species, known as a mediator, facilitates electron transfer between an...
• Redox polymerA polymer that contains electrochemically active functional groups capable of undergoing reversible oxidation...
• Redox potentialThe electromotive force of a reversible galvanic cell in which one electrode is the standard hydrogen...
• Reduced adsorptionThe amount of a substance adsorbed per unit area of an adsorbent surface, normalized by a reference quantity...
• Reduced mobile phase velocityA dimensionless parameter in chromatography that normalizes the mobile phase velocity by the diffusion...
• Reduced osmotic pressureThe osmotic pressure (Π) of a solution divided by its concentration (c), expressed as Π/c. This quantity is...
• Reduced plate heightA dimensionless measure of chromatographic column efficiency, calculated by dividing the plate height by the...
• Reduced pressureA dimensionless quantity representing the ratio of a substance's actual pressure to its critical pressure...
• Reduced sampleA portion of a laboratory sample obtained by a defined procedure, intended for further preparation or direct...
• Reduced speciesA chemical entity that has gained electrons or hydrogen atoms, or lost oxygen atoms, in a chemical reaction...
• Reduced temperatureA dimensionless quantity representing the ratio of a substance's actual absolute temperature to its critical...
• Reduced viscosityThe ratio of the specific viscosity of a polymer solution to the mass concentration of the polymer. It...
• ReducingDescribing a process or substance that causes a reduction reaction in another chemical species. This involves...
• ReductionA chemical process involving the gain of electrons by an atom, ion, or molecule, or a decrease in its...
• Reductive eliminationA reaction in organometallic chemistry where two ligands on a metal center combine to form a new bond and...
• ReductonesOrganic compounds containing an enediol group (-C(OH)=C(OH)-) adjacent to a carbonyl group, which allows them...
• Redundancy hypothesisA concept in ecology proposing that some species within an ecosystem have overlapping functions, so the loss...
• Re-extractionA process in liquid-liquid extraction where a solute that has been extracted into one solvent phase is...
• Reference atomAn atom within a molecule that serves as a fixed point for defining the stereochemistry or connectivity of...
• Reference concentrationAn estimate of a continuous inhalation exposure to a substance that is likely to be without an appreciable...
• Reference dataA set of critically evaluated data for a specific property of a well-characterized substance, compiled and...
• Reference doseAn estimated daily exposure to a chemical that is not expected to cause adverse health effects over a...
• Reference electrodeAn electrode that maintains a stable and known potential, serving as a benchmark against which the potential...
• Reference examination procedureA meticulously documented and validated examination procedure that serves as a benchmark for accuracy and...
• Reference examination standardA standard designated for calibrating a reference examination procedure or for verifying the trueness of a...
• Reference flux densityThe rate of flow of particles or radiation per unit area from a known, stable source, used for calibration or...
• Reference individualA hypothetical person with defined physiological and anatomical characteristics, used as a standard for...
• Reference intervalThe interval between two reference limits, which are derived from a reference population and used for...
• Reference ionAn ion of known mass-to-charge ratio that is introduced into a mass spectrometer to calibrate the mass scale...
• Reference laboratoryA laboratory that provides measurements with the highest metrological quality for a specific quantity or...
• Reference limitA specific value within a reference interval that serves as a threshold for distinguishing between normal and...
• Reference materialA substance or object with one or more properties that are sufficiently homogeneous and well-established to...
• Reference material certificateA document accompanying a certified reference material that states one or more property values, their...
• Reference material certificationThe procedure for determining one or more property values of a material, including their uncertainties and...
• Reference material certification reportA detailed document outlining the entire process of characterizing a reference material, from its production...
• Reference material producerAn organization that manufactures and certifies reference materials according to defined quality management...
• Reference methodAn analytical procedure of established and demonstrated accuracy for a specific measurement purpose. It is...
• Reference nominal property valueA nominal property value that is used as a reference for comparison or calibration purposes. This value is...
• Reference populationA group of individuals selected according to specific criteria, whose biological or physiological...
• Reference procedureA thoroughly characterized and validated experimental method for measuring a specific property of a material...
• Reference sample groupA group of subjects selected to represent a defined population, from which biological samples are collected...
• Reference sedimentA sediment sample collected from an area known to be uncontaminated or minimally contaminated, used as a...
• Reference siteA location that represents the natural or undisturbed environmental conditions of an ecosystem, used as a...
• Reference stateA specific state of a substance, defined by a set of conditions, used as a baseline for comparing its...
• Reference toxicantA chemical substance with a known and consistent toxicity, used in ecotoxicological tests to assess the...
• Reference toxicity testA standardized toxicity assay conducted using a reference toxicant to evaluate the health and sensitivity of...
• Reference valueA quantitative estimate of the concentration or level of a substance in a biological fluid, tissue, or...
• Reference value pH standardA solution with a precisely known and reproducible pH value, used for calibrating pH meters and establishing...
• ReflectanceThe ratio of the radiant flux reflected by a surface to the radiant flux incident upon it. This quantity...
• Reflected powerThe portion of incident electromagnetic radiation that is returned from a surface or interface. This power is...
• ReflectionThe phenomenon where electromagnetic radiation or other waves encounter a boundary between two different...
• Reflection electron energy loss spectroscopyA surface-sensitive analytical technique that measures the energy distribution of electrons scattered from a...
• Reflection high energy electron diffractionA surface-sensitive analytical technique that uses a high-energy electron beam incident at a grazing angle to...
• Reflection-absorption at grazing incidenceA spectroscopic technique for studying thin films on reflective surfaces, where p-polarized infrared or other...
• Reflection-absorption infrared spectroscopyA surface-sensitive analytical technique that measures the infrared absorption spectrum of molecules adsorbed...
• Reflector voltageThe electrical potential applied to the reflector electrode in a reflectron time-of-flight mass spectrometer...
• ReflectronAn ion mirror used in a time-of-flight mass spectrometer to increase mass resolution by correcting for the...
• ReflexAn involuntary and rapid response to a stimulus, mediated by the nervous system without conscious thought...
• Refraction effectsThe changes in the direction of light or other electromagnetic radiation as it passes from one medium to...
• Refractive index incrementThe rate of change of the refractive index of a polymer solution with respect to the concentration of the...
• RegenerationThe process of restoring a spent catalyst or adsorbent to its active state, allowing it to be reused in a...
• Regioirregular polymerA polymer in which the monomer units are connected in a non-uniform or random head-to-tail, head-to-head, or...
• RegionA geographical area characterized by specific environmental conditions, ecological features, or human...
• Regiorandom polymerA polymer characterized by a statistically random distribution of monomer connectivity, meaning there is no...
• Regioregular polymerA polymer in which the monomer units are connected in a highly ordered and uniform head-to-tail or...
• RegioselectivityThe preference for bond making or breaking at one specific site over other possible sites in a molecule...
• Regression analysisA set of statistical processes for estimating the relationships among variables, specifically to model a...
• Regular adjacent re-entry modelA model describing the folding of polymer chains within lamellar crystals, where a chain folds back on itself...
• Regular blockA block within a block copolymer that consists of constitutional repeating units of a single type, arranged...
• Regular cokeA type of coke characterized by a relatively disordered structure with small, poorly oriented graphitic...
• Regular dendrimerA dendrimer composed of identical dendrons attached to a central core, where each dendron has a uniform and...
• Regular dendrimer moleculeA macromolecule characterized by a highly symmetrical and perfectly branched structure, where all dendrons...
• Regular dendronA perfectly branched polymeric arm that extends from a central core in a dendrimer, characterized by a...
• Regular macromolecular rotaxaneA macromolecular rotaxane in which the cyclic components are threaded onto a polymer chain, and both the...
• Regular macromoleculeA macromolecule whose structure can be described by a single type of constitutional repeating unit in a...
• Regular oligomer moleculeAn oligomer molecule composed of a single type of constitutional repeating unit arranged in a single, defined...
• Regular polymerA polymer whose molecules consist of a single type of constitutional repeating unit arranged in a single...
• Regular single-strand polymerA polymer whose macromolecules are composed of a single type of constitutional repeating unit, connected in a...
• Regular surfaceA surface characterized by a uniform arrangement of atoms or molecules, exhibiting a high degree of order and...
• Regular surface siteA specific location on a solid surface where the atoms are arranged in a periodic and ordered manner...
• RegularizationA technique employed in computational modeling and machine learning to prevent overfitting by adding a...
• Regularized discriminant analysisA statistical classification method that extends linear and quadratic discriminant analysis by introducing...
• Regulator geneA gene that codes for a protein or ribonucleic acid (RNA) molecule that controls the expression of other...
• Regulatory doseA specific dose level of a substance that is established by regulatory authorities as safe or acceptable for...
• Regulatory idiotopeA specific antigenic determinant on an antibody or T-cell receptor that can be recognized by other immune...
• Regulatory sequenceA segment of DNA or RNA that influences the transcription or translation of a gene, without coding for a...
• Regulatory T cellA subpopulation of T lymphocytes that actively suppresses the immune response to maintain self-tolerance and...
• Rehm-Weller equationAn empirical equation that describes the rate constant for photoinduced electron transfer reactions in...
• Reinforced reaction injection mouldingA manufacturing process that combines reaction injection moulding with the incorporation of reinforcing...
• ReinforcementA process in behavioral psychology where a consequence following a behavior increases the likelihood of that...
• Reissert compoundsA class of N-acyl derivatives of 1,2-dihydroquinoline-2-carbonitrile or...
• RejectionAn immune response mounted by the recipient's body against transplanted cells, tissues, or organs...
• Rejection intervalA range of values for a measured quantity that, if obtained, indicates that a product, process, or system...
• RelativeDescribing a quantity that is expressed as a ratio of two quantities of the same kind, making it...
• Relative adsorptionThe amount of a component adsorbed at an interface, expressed relative to the adsorption of another component...
• Relative atomic massThe average mass of atoms of an element, considering the isotopic abundance, compared to 1/12th the mass of a...
• Relative biological effectivenessA factor used in radiobiology to compare the biological damage caused by different types of ionizing...
• Relative configurationThe spatial arrangement of atoms or groups in a chiral molecule compared to another chiral molecule, without...
• Relative countingA method in radioanalytical chemistry where the activity of a radioactive sample is determined by comparing...
• Relative counting efficiencyThe ratio of the counting efficiency of a detector for a specific radionuclide under particular conditions to...
• Relative electrode potentialThe potential difference between an electrode and a reference electrode, measured under specific conditions...
• Relative errorA measure of the uncertainty of a measurement relative to the magnitude of the measurement itself. It is...
• Relative excess riskA measure of the proportional increase in risk in an exposed population compared to an unexposed population...
• Relative hardnessA measure of the resistance of a chemical species to deformation of its electron cloud, often related to the...
• Relative humidityThe ratio of the partial pressure of water vapor in the air to the saturation vapor pressure of water at the...
• Relative instrument spectral response functionA function that characterizes the variation in an analytical instrument's output signal as a function of a...
• Relative isotope-ratio differenceA measure of the difference in the isotopic composition of a sample compared to a reference material...
• Relative isotopic sensitivity factorA scaling factor used in dynamic secondary-ion mass spectrometry to convert the measured ion intensity of a...
• Relative mass accuracyA measure of the precision of a mass measurement, expressed as the absolute mass error divided by the true...
• Relative micellar massThe ratio of the average mass of a micelle to 1/12 of the mass of an atom of carbon-12. This dimensionless...
• Relative molar massThe ratio of the molar mass of a substance to the molar mass of a reference substance, typically 1/12 of the...
• Relative molecular massThe ratio of the average mass of a molecule of a substance to 1/12 of the mass of an atom of carbon-12. This...
• Relative molecular-mass exclusion limitThe maximum molecular mass of a solute that can penetrate the pores of a chromatographic stationary phase in...
• Relative permeabilityA dimensionless quantity that describes the ease with which a magnetic field can be established in a...
• Relative permittivityA dimensionless quantity that describes how an electric field affects and is affected by a dielectric medium...
• Relative photonic efficiencyThe ratio of the rate of a given photocatalytic reaction to the rate of a reference photocatalytic reaction...
• Relative preconcentrationA process in analytical chemistry where the concentration of an analyte in a sample is increased relative to...
• Relative quantificationA method of determining the amount of an analyte in a sample by comparing its signal to that of a reference...
• Relative resolutionA measure of the ability of an analytical instrument, such as an electron spectrometer, to distinguish...
• Relative retardationA measure in chromatography that compares the movement of a solute to the movement of the mobile phase front...
• Relative retentionThe ratio of the adjusted retention time or volume of a substance to that of a standard substance, obtained...
• Relative riskA measure of the likelihood of an event occurring in an exposed group compared to the likelihood of the event...
• Relative sputtering rateThe ratio of the sputtering rate of a specific element or isotope within a sample to the sputtering rate of a...
• Relative standard deviationA measure of the precision of a set of measurements, expressed as the standard deviation divided by the...
• Relative systemic availabilityA comparison of the systemic exposure to a drug after administration by one route or formulation, relative to...
• Relative uncertaintyThe uncertainty of a measurement expressed as a fraction or percentage of the measured value. It indicates...
• Relative viscosityThe ratio of the viscosity of a polymer solution to the viscosity of the pure solvent at the same temperature...
• Relative viscosity incrementA measure of the increase in viscosity of a polymer solution relative to the pure solvent, calculated as the...
• Relative volumic massThe ratio of the density of a substance to the density of a reference substance, both measured under...
• Relativistic effectsCorrections to the electronic structure and properties of atoms and molecules that arise from the theory of...
• RelaxantA substance that reduces tension or stiffness in muscles or other tissues. These agents act on the central...
• RelaxationThe process by which a system returns to its equilibrium state after being perturbed. This involves the...
• Relaxation energyThe energy difference between the initial and final states of a system, where the final state has undergone...
• Relaxation reagentA paramagnetic substance added to a sample in nuclear magnetic resonance (NMR) spectroscopy to reduce the...
• Relaxation spectrumA distribution function that describes the range of relaxation times present in a viscoelastic material, such...
• Relaxation timeThe characteristic time constant for a system to return to its equilibrium state after a sudden perturbation...
• ReleaserA chemical substance added to a sample in analytical procedures to prevent or overcome interferences from...
• RemA unit of dose equivalent, representing the biological effect of ionizing radiation on human tissue. It is...
• Remedial investigationA detailed study conducted at a contaminated site to characterize the nature and extent of contamination...
• Remedial investigation and feasibility studyA two-part process used to evaluate contaminated sites, particularly under regulatory frameworks like the...
• RemediationThe process of reversing or stopping environmental damage, particularly the removal of pollutants or...
• RemedyA specific action or set of actions undertaken to address and mitigate environmental contamination at a site...
• Remote sensingA collection of methods for gathering information about an object, area, or phenomenon from a distance...
• RenalRelating to the kidneys, the pair of organs responsible for filtering waste products from the blood and...
• Renal plasma flowThe volume of blood plasma that passes through the kidneys per unit of time, serving as a measure of kidney...
• Renner-Teller effectA vibronic coupling phenomenon occurring in linear polyatomic molecules when an electronic state is...
• ReorganizationA process in which a polymer that has already undergone primary crystallization experiences further...
• Reorganization energyThe energy required to distort the nuclear geometry of a reactant molecule and its surrounding solvent...
• Repeat action dosage formA pharmaceutical formulation designed to release a drug in two or more discrete doses or at different rates...
• RepeatabilityThe precision of measurements obtained under the same conditions, including the same operator, instrument...
• Repeatability conditionA set of conditions under which independent test results are obtained with the same method on identical test...
• Repeatability condition of measurementA set of conditions under which independent measurement results are obtained with the same measurement...
• RepellentA substance that deters an organism from approaching or settling on a particular area or surface. Repellents...
• ReperfusionThe restoration of blood flow to an organ or tissue that has experienced a period of ischemia, or inadequate...
• Repetition rateThe frequency at which pulses of radiation are emitted by a pulsed source, such as a laser. It quantifies how...
• Repetition timeThe time interval between successive excitations of the same nuclear spin system in nuclear magnetic...
• Replacement nameA systematic name for a chemical compound that is formed by replacing a specific atom or group in a parent...
• Replacement operationA conceptual operation in chemical nomenclature where an atom or group in a parent structure is formally...
• Replicate sampleMultiple portions of a single sample that are analyzed independently using the same analytical procedure...
• Replicate samplingThe process of collecting two or more independent samples under conditions as similar as possible from the...
• ReplicationThe biological process by which a deoxyribonucleic acid (DNA) molecule is duplicated to produce two identical...
• RepolarizationThe process by which the membrane potential of an excitable cell, such as a neuron or muscle cell, returns to...
• ReportA document or electronic file that presents the final results of a chemical analysis in a structured and...
• Reporter probeA molecule designed to bind to a specific target analyte and produce a measurable signal upon binding. It...
• ReprecipitationA purification technique involving the dissolution of a previously formed precipitate, followed by its...
• RepressionThe decrease in the rate of synthesis of an enzyme or other protein in a cell, typically in response to the...
• ReproducibilityThe precision of measurements obtained under different conditions, such as different operators, instruments...
• Reproducibility conditionA condition under which independent test results are obtained with the same method on identical test items in...
• Reproductive cycleThe sequence of physiological events occurring in an organism that lead to the production of offspring. This...
• Reproductive senescenceThe age-related decline in reproductive function in an organism, eventually leading to the cessation of...
• Reproductive toxicantA substance or agent that causes adverse effects on the reproductive system of an organism, or on the...
• Reproductive toxicityThe adverse effects of a substance on sexual function and fertility in adult males and females, as well as...
• Reproductive toxicity testAn experimental procedure designed to evaluate the potential of a chemical or agent to cause adverse effects...
• Reproductive toxicologyThe scientific discipline that studies the adverse effects of chemical, physical, or biological agents on the...
• Reproductive valueThe expected number of future offspring an individual of a given age and sex will produce. This ecological...
• ReptationA model describing the motion of long, entangled polymer chains in a dense melt or concentrated solution...
• Repulsive potential-energy surfaceA representation of the potential energy of a reacting system as a function of the positions of its...
• RequirementA specified need or expectation that must be met by a product, process, or system. In analytical chemistry...
• Rescue effectA phenomenon in metapopulation dynamics where a declining local population is saved from extinction by...
• Reserve capacityThe ability of an organ or system to perform its functions beyond the normal physiological demands. This...
• ReservoirA component of the environment, such as soil, water, air, or a living organism, that retains a chemical...
• Residence timeThe average length of time a substance remains within a specific system or compartment before being removed...
• Residential macrophageA type of macrophage that resides long-term within a specific tissue, as opposed to those that migrate to...
• Residual currentThe small current that flows through an electrochemical cell when no faradaic reaction is occurring at the...
• Residual dipolar couplingThe small, non-zero dipolar coupling observed in nuclear magnetic resonance (NMR) spectroscopy when molecules...
• Residual emission anisotropyThe non-zero anisotropy value observed in fluorescence emission after all rotational motion of the...
• Residual fuel/oilA heavy, viscous petroleum product remaining after the lighter, more volatile fractions have been removed...
• Residual gas analyserA type of mass spectrometer designed to measure the partial pressures of gases present in a vacuum system. It...
• Residual liquid junction errorThe small, unavoidable potential difference that remains across the interface between two electrolyte...
• Residual riskThe risk that remains after all risk management and mitigation measures have been implemented to reduce an...
• Residual spectrum/background spectrumA spectrum obtained from a sample or environment that contains signals from components other than the analyte...
• ResidueA specified substance, including any of its metabolites, degradation products, or reaction products, that...
• ResilienceThe capacity of an ecosystem, community, or organism to absorb disturbance and reorganize while undergoing...
• ResistA radiation-sensitive polymeric material applied as a thin film to a substrate to enable pattern transfer...
• Resist polymerA macromolecule specifically designed for use in resist formulations, where its chemical structure dictates...
• Resist profileThe cross-sectional shape of a resist feature after the development step in a lithographic process. This...
• Resist stripThe process of completely removing a patterned resist layer from a substrate after it has served its purpose...
• ResistanceThe opposition offered by a conductor to the passage of an electric current, resulting in the conversion of...
• ResistivityAn intrinsic property of a material that quantifies its opposition to the flow of electric current...
• ResolutionA measure of the ability of an analytical instrument to distinguish between two closely spaced signals in a...
• Resolution of a designA characteristic of a fractional-factorial experimental design that describes the degree to which main...
• Resolution: peak width definitionA measure of the ability of a mass spectrometer to distinguish between two ions of slightly different...
• Resolution phaseThe final stage of a neurotoxicological response, characterized by the gradual return of physiological...
• Resolving powerThe ability of an optical instrument or analytical technique to distinguish between two closely spaced...
• Resolving timeThe minimum time interval required between two consecutive events for a radiation detector system to register...
• Resolving time correctionAn adjustment applied to the observed count rate in nuclear measurements to account for pulses that are not...
• ResonanceA concept in valence bond theory describing the delocalization of electrons within molecules or polyatomic...
• Resonance absorption techniqueA spectroscopic method where a sample absorbs radiation at a specific frequency corresponding to an...
• Resonance cross-sectionThe effective area presented by a nucleus for the resonant absorption of a gamma ray in Mössbauer...
• Resonance effect magnitudeA measure of the intensity of a resonance line in a Mössbauer spectrum, representing the fractional change in...
• Resonance energyThe difference in energy between the actual delocalized structure of a molecule and the most stable...
• Resonance fluorescenceThe re-emission of radiation by an atom or molecule at the same wavelength as the absorbed radiation...
• Resonance fluorescence techniqueA spectroscopic method where a species absorbs radiation at a specific wavelength and then re-emits light at...
• Resonance formA Lewis structure that represents one of the possible electron arrangements for a molecule or ion that...
• Resonance hybridThe actual electronic structure of a molecule or ion that cannot be adequately represented by a single Lewis...
• Resonance integralA parameter in molecular orbital theory that describes the interaction energy between two atomic orbitals on...
• Resonance ion ejectionA technique for selectively removing ions from an ion trap mass spectrometer by applying a supplementary...
• Resonance lampA type of spectral lamp that emits radiation at specific wavelengths corresponding to the resonance lines of...
• Resonance lineA spectral line corresponding to a transition between the ground electronic state and the lowest excited...
• Resonance neutronsNeutrons with kinetic energies in an intermediate range where the probability of their capture by a nucleus...
• Resonance radiationElectromagnetic radiation that is absorbed by an atom or molecule, causing it to transition from its ground...
• Resonance Raman scatteringA spectroscopic phenomenon where the intensity of Raman scattered light is significantly enhanced when the...
• Resonance reactionA nuclear reaction that occurs with a significantly enhanced probability when the energy of the incident...

726 of 13,678 terms in Chemistry terminology (MLC-0109). Request the full dataset.