Chemistry terminology · MLC-0109

Chemistry terms: Q (86)

• q2A statistical measure used in quantitative structure-activity relationship (QSAR) models to assess the...
• Qa antigenA non-classical major histocompatibility complex (MHC) class I molecule expressed on the surface of certain...
• Q-e schemeA semi-empirical model used to predict the monomer reactivity ratios in radical copolymerization. The 'Q'...
• Q-switched laserA type of laser that produces high-intensity, short-duration pulses of light by modulating the quality factor...
• QTc intervalA heart-rate corrected measurement of the time between the start of the Q wave and the end of the T wave in...
• Quadratic discriminant analysisA statistical classification method that separates observations into two or more classes by fitting a...
• Quadratic field reflectronAn ion mirror in a time-of-flight mass spectrometer that uses an electric field in which the potential varies...
• Quadratic meanThe square root of the arithmetic mean of the squares of a set of values. To calculate it, each value in a...
• Quadrature detectionA method in spectroscopy, particularly nuclear magnetic resonance (NMR), where two detectors are used to...
• QuadriplegiaParalysis affecting all four limbs, including the arms and legs, as well as the torso. This condition results...
• Quadro-A numerical prefix indicating four identical units or components within a chemical structure or complex. It...
• Quadrupolar axializationA process used in ion trap mass spectrometry to reduce the initial radius of an ion's cyclotron motion and...
• Quadrupolar nuclideAn atomic nucleus that possesses a nuclear electric quadrupole moment, meaning its charge distribution is not...
• Quadrupolar relaxationA nuclear magnetic resonance (NMR) relaxation mechanism that arises from the interaction of a quadrupolar...
• Quadrupole ion storage trapA device used in mass spectrometry to confine and store ions using a combination of static and oscillating...
• Quadrupole mass analyserA mass spectrometer component consisting of four parallel rods to which radiofrequency and direct current...
• Quadrupole splittingThe splitting of nuclear energy levels due to the interaction between a nucleus's electric quadrupole moment...
• Quadrupole time-of-flightA hybrid mass spectrometry technique combining a quadrupole mass filter with a time-of-flight (TOF) mass...
• Qualitative analysisThe identification of the chemical constituents present in a sample, without necessarily determining their...
• Qualitative elemental specificityThe ability of an analytical method to detect and identify a specific element in a sample without...
• QualityThe degree to which a set of inherent characteristics of an object, such as a product, process, or...
• Quality assuranceA systematic set of activities designed to provide confidence that a product or service will satisfy given...
• Quality controlThe operational techniques and activities used to fulfill requirements for quality, focusing on identifying...
• Quality control materialA material or substance used to assess the performance of a measurement procedure and monitor its stability...
• Quality criteriaSpecific scientific requirements or standards established for environmental components, such as water, soil...
• Quality factorA dimensionless value used in dosimetry that relates the absorbed dose of ionizing radiation to the...
• Quality guidelinesNon-enforceable recommendations or benchmarks for environmental quality, often developed to protect specific...
• Quality improvementSystematic activities designed to enhance the effectiveness and efficiency of processes, products, or...
• Quality managementThe coordinated activities of an organization to direct and control itself with regard to quality. This...
• Quality management systemA set of interrelated or interacting elements that an organization uses to direct and control how quality...
• Quality manualA document that specifies the quality management system of an organization. It outlines the scope of the...
• Quality objectiveA specific, measurable goal related to quality that an organization aims to achieve. These objectives are...
• Quality of solventA measure of how well a solvent interacts with a polymer, influencing the polymer's conformation and...
• Quality planA document specifying the quality procedures and associated resources to be applied by whom and when to a...
• Quality planningThe part of quality management focused on setting quality objectives and specifying the operational processes...
• Quality policyA formal statement by top management of an organization's overall intentions and direction with regard to...
• Quality standardsLegally enforceable limits or concentrations of pollutants in environmental media, such as water, air, or...
• QuantalDescribing a biological response that is all-or-none in nature, meaning it either occurs or does not occur in...
• Quantal effectA biological response that is characterized by an all-or-none outcome in an individual organism, rather than...
• Quantitation by concatenated tryptic peptidesA method for absolute protein quantitation in mass spectrometry that involves creating a synthetic protein...
• Quantitative analysisThe determination of the absolute or relative abundance of one or more substances present in a sample. This...
• Quantitative polymerase chain reactionA molecular biology technique that measures the amplification of a targeted DNA molecule in real-time during...
• Quantitative structure-activity relationshipA computational modeling approach that correlates the chemical structure of a set of compounds with their...
• Quantitative structure-activity relationshipsMathematical models that correlate the structural or physicochemical properties of chemical compounds with...
• Quantitative structure-metabolism relationshipA mathematical model that correlates the structural properties of chemical compounds with their metabolic...
• Quantitative structure-property relationshipA mathematical model that correlates the structural features of a set of chemical compounds with their...
• QuantityA property of a phenomenon, body, or substance that can be expressed as a magnitude and a unit. It represents...
• Quantity calculusA system of algebra for physical quantities where equations are written with the quantity symbols themselves...
• Quantity of dimension oneA physical quantity for which all the exponents of the base quantities in its dimension product are zero...
• Quantized internal energyThe discrete energy levels associated with the internal motions of a molecule, such as vibrational...
• QuantumA discrete, indivisible unit of energy or other physical quantity, representing the smallest possible amount...
• Quantum cascade laserA semiconductor laser that emits electromagnetic radiation in the mid- to far-infrared region of the...
• Quantum confinement effectThe phenomenon where the electronic properties of a material change significantly when its dimensions are...
• Quantum counterA photoluminescent species used to determine the quantum yield of a light source, particularly in the...
• Quantum efficiencyThe ratio of the number of specific desired events (e.g., emitted photons, electrons generated) to the number...
• Quantum mechanics/molecular mechanicsA computational approach that combines quantum mechanics (QM) for a chemically reactive region of a system...
• Quantum tunneling polymer compositeA composite material where electrical conduction occurs primarily through electron tunneling between...
• Quantum yieldThe number of times a specific photochemical or photophysical event occurs per photon absorbed by a system...
• Quarter-transition-time potentialThe potential measured at one-quarter of the transition time in chronopotentiometry. The transition time is...
• Quartet stateAn electronic state of an atom or molecule characterized by a total spin angular momentum quantum number (S)...
• Quartz atomizerA device constructed from quartz, used to convert a liquid sample into a fine aerosol for introduction into...
• Quartz-iodine lampA type of incandescent lamp that uses a tungsten filament enclosed in a compact quartz envelope filled with...
• Quasi-classical trajectory methodA computational method used in chemical dynamics to simulate the trajectories of atoms in a reacting system...
• Quasi-enantiomersPairs of molecules that are structurally very similar and behave as enantiomers in certain contexts, but are...
• Quasi-equilibriumA state in a chemical system where certain processes are in equilibrium, while others are not, or where a...
• Quasi-equilibrium theoryA statistical theory describing the unimolecular decomposition of ions in the gas phase, particularly...
• Quasi-molecular ionAn ion formed in a mass spectrometer by the interaction of a neutral analyte molecule with an ion from a...
• QuasiparticleAn emergent entity in a many-body system that behaves like a particle, simplifying the description of complex...
• Quasi-racemic compoundA crystalline compound formed between two enantiomers that are structurally very similar but not identical...
• Quasi-reference electrodeAn electrode that maintains a relatively stable potential during an electrochemical measurement, but whose...
• Quasi-single-strand polymerA polymer whose constitutional repeating units are connected in a linear fashion, forming a single main...
• Quaternary ammonium compoundsOrganic compounds containing a positively charged nitrogen atom bonded to four organic substituents, which...
• Quaternary structureThe highest level of protein organization, referring to the arrangement of multiple polypeptide chains...
• QuEChERS (quick, easy, cheap, effective, rugged and safe) extractionA sample preparation method for the analysis of pesticide residues in food and agricultural products. It...
• QuencherA chemical species that reduces the intensity of fluorescence or phosphorescence from an excited molecule...
• QuenchingThe deactivation of an excited state molecule or atom through interaction with another chemical species...
• Quenching correctionA mathematical adjustment applied to data from liquid scintillation counting to compensate for reduced...
• QuickeningThe first perception of fetal movement by a pregnant individual. This subjective sensation marks a milestone...
• QuinarenesA class of organic compounds characterized by a quinoid ring system fused to one or more aromatic rings...
• QuinhydronesCharge-transfer complexes formed from the co-crystallization of equimolar amounts of a quinone and its...
• QuinomethanesA class of conjugated non-benzenoid compounds containing a cyclohexadiene ring system with exocyclic double...
• Quinone diazidesA class of compounds also known as diazooxides, which are formally derived from quinones by the replacement...
• QuinonesA class of organic compounds characterized by a cyclic diketone structure derived from an aromatic compound...
• QuinoniminesCompounds structurally related to quinones, where one or both of the carbonyl oxygen atoms are replaced by an...
• QuinonoximesOrganic compounds derived from quinones where one or both of the carbonyl oxygen atoms are replaced by an...
• Quotient methodA risk assessment approach used in ecotoxicology to evaluate the potential hazard of a contaminant to an...

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