Gold Book Terms

'A' value A-factor \(A\)ab initio calculations ab initio quantum mechanical methods abatement abeo- abiological abiotic abiotic transformation absolute activation analysis absolute activity \(\lambda\)absolute configuration absolute counting absolute electrode potential absolute full energy peak efficiency absolute lethal concentration \(\text{LC}_{100}\)absolute lethal dose \(\text{LD}_{100}\)absolute photopeak efficiency absolute preconcentration absorbance matching absorbance \(A\)absorbed (spectral) photon flux density absorbed (spectral) radiant power density absorbed dose of a substance absorbed dose \(D\)absorbed electron coefficient absorbed electrons absorber absorptance \(\alpha\)absorption absorption coefficient absorption coefficient absorption cross-section \(\sigma\)absorption factor absorption intensity absorption line absorption pathlength absorption spectrum absorptivity abstraction abstraction process abundance sensitivity ac accelerating voltage scan \(\text{V}\)acceleration energy acceleration of free fall \(g\)acceleration \(a\)accelerator acceptable daily intake acceptable daily intake \(\text{ADI}\)acceptor number \(\text{AN}\)accommodation coefficient accretion accuracy accuracy acenes acetals acetogenins acetonides acetylene black acetylenes acetylides Acheson graphite achiral achirotopic aci-nitro compounds acid acid anhydrides acid deposition acid rain acid thioanhydrides acid-labile sulfur acid–base indicator acid–base titration acidimetric titration acidity acidity constant acidity function acidosis actinic actinic flux \(S_{\lambda}\)actinism actinometer action spectrum activated adsorption process activated carbon activated charcoal activated complex activation activation analysis (nuclear) activation cross-section activation energy activation activation activation reaction activator active centre active medium active metal active site active solid active species active state active transport activity activity \(a\)activity coefficient \(f\),\(\gamma \)activity \(A\)acute toxicity acyl anions acyl carbenes acyl cations acyl groups acyl halides acyl radicals acyl shift (1,2-, 1,3-, photochemical) acyl species acylals acylium ions acyloins acyloxyl radicals added hydrogen addend addition addition reaction additive additive name additivity additivity principle adduct adduct ion adhesional wetting adiabatic adiabatic electron transfer adiabatic ionization adiabatic lapse rate adiabatic photoreaction adiabatic transition-state theory adiabatic treatments of reaction rates adjacent re-entry model adjusted retention volume adjuvant ADMR adsorbate adsorbent adsorber adsorption adsorption capacity adsorption chromatography adsorption complex adsorption current adsorption hysteresis adsorption indicator adsorption isobar adsorption isostere adsorption isotherm adsorption isotherm adsorptive advancement advection adverse effect aeration aerobe aerobic aerobic conditions aerogel aeromete aerometric measurement aerosol aerosol hydrolysis affine chain behaviour affinity chromatography affinity of reaction \(A\)after mass analysis ageing of precipitate agglomerate agglomerate agglomeration (except in polymer science) agglomeration agglutination aggregate aggregation (except in polymer science) aging aglycon agonist agostic agostic interaction agranular carbon air contaminant air mass air monitoring station air pollutant air pollution air pollution index air pollution survey air quality characteristic air resource management air sampling network air-lift bioreactor Aitken particles albedo albumin alcogel alcoholates alcohols alcoholysis aldaric acids aldazines aldehydes aldimines alditols aldoketoses aldonic acids aldoses aldoximes alert levels alicyclic compounds aliphatic compounds aliquot alkalimetric titration alkaloids alkalosis alkanes alkanium ions alkene photocycloaddition alkene photodimerization alkene photoisomerization alkene photorearrangement alkenes alkoxides alkoxyamines alkyl groups alkyl radicals alkylenes alkylidene groups alkylideneamino carbenes alkylideneaminoxyl radicals alkylideneaminyl radicals alkylidenes alkylidynes alkynes allele allenes allo- allometric allosteric enzymes allostery allotriomorphic transition allotropes allotropic transition allylic groups allylic intermediates allylic substitution reaction alternancy symmetry alternant alternating copolymer alternating copolymerization alternating current alternating voltage altocumulus cloud altostratus cloud AM 0 sunlight AM 1 sunlight amalgam lamp ambident ambient air ambient air quality ambo Ames/salmonella test amic acids amide hydrazones amide oximes amides amidines amidium ions amidrazones aminals amine imides amine imines amine oxides amine ylides amines aminimides aminium ions aminiumyl radical ions amino radicals amino sugars amino-acid residue aminonitrenes aminooxyl radicals aminoxides aminoxyl radicals aminyl oxides aminyl radicals aminylenes aminylium ions ammonium compounds ammonium imines ammonium ylides ammoniumyl radical ions amorphous carbon amount concentration \(c\)amount fraction \(x\),\(y\)amount of substance \(n\)amount-of-substance concentration amount-of-substance fraction \(x\)ampere amperometric detection method amphipathic amphiphilic amphiprotic (solvent) ampholytes ampholytic polymer amphoteric amplification reaction amplitude of alternating current amplitude of alternating voltage anabolism anaerobe anaerobic anaesthetic analgesic analogue metabolism analogue to digital converter (pulse) analyte analytical function analytical instrument analytical intercomparison analytical portion analytical pyrolysis analytical quality control analytical radiochemistry analytical sample analytical solution analytical solution calorimetry analytical unit anation anchimeric assistance aneroid barometer Anger camera angle angle of observation angle of optical rotation \(\alpha\)angle strain angular distribution angular frequency \(\omega\)angular momentum \(L\)angular overlap model (AOM) anhydrides anhydro bases anilides anils anion anion exchange anion exchanger anion radical anion-exchange polymer anionic polymer anionic polymerization anionotropic rearrangement anisometric anisotropy annelation annihilation annulation annulenes annulenylidenes anode anodic transfer coefficient anomeric effect anomers ansa compounds antagonism antagonist antarafacial anthelmintic anthocyanidins anthocyanins anti anti-Compton γ-ray spectrometer anti-Hammond effect anti-Markownikoff addition anti-Stokes shift anti-Stokes type radiation (fluorescence) anti-thixotropy antiaromatic compounds antiaromaticity antibiotic antibody antibonding molecular orbital anticholinergic anticircular elution anticlinal anticlined structures anticodon anticyclone antiferroelectric transition antiferromagnetic transition antigen antihelminth antimetabolite antimony–xenon lamp (arc) antimycotic antiparticle antiperiplanar antipodes antiprismo- antiresistant antiserum antisymmetry principle ap apex apex current apex potential aphicide apical (basal, equatorial) apicophilicity apo- in carotenoid nomenclature apoenzyme apoprotein apoptosis apparent (quantity) apparent lifetime apparent viscosity appearance energy appearance potential appearance temperature \(T_{\text{app}}\)applied potential aprotic (solvent) aquagel aquation arachno- Archibald's method area area of interface area viscosity areic arene epoxides arene oxides arenes arenium ions arenols arenonium ions argon ion laser arithmetic mean aromatic aromatic photocycloaddition aromaticity arrester Arrhenius A factor \(A\)Arrhenius energy of activation Arrhenius equation arsanes arsanylidenes arsanylium ions arsenides arsine oxides arsines arsinic acids arsinidenes arsinous acids arsonic acids arsonium compounds arsonous acids arsoranes artificial graphite artificial neural networks artificial radioactivity aryl cations aryl groups arylene groups aryne ascending elution ash ashing aspirator assay assay kit association association reaction associative desorption associative ionization associative surface reaction asym- asymmetric asymmetric carbon atom asymmetric centre asymmetric destruction asymmetric film asymmetric induction asymmetric membrane asymmetric photochemistry asymmetric synthesis asymmetric transformation asymmetry asymmetry potential atactic macromolecule atactic polymer atmosphere atmosphere atmospheric pressure ionization [obsolet atom atom-atom polarizability atom-bond polarizability atom–molecule complex mechanism atomic charge atomic fluorescence atomic laser atomic mass constant atomic mass \(m_{\text{a}}\)atomic mass unit atomic number \(Z\)atomic orbital \(\psi\),\(\varphi\),\(\chi\)atomic ring-sector atomic spectral lines atomic symbol atomic units atomic weight atomization atomization surface temperature \(T_{\text{s}}\)atomize atomizer atropisomers attachment attenuance filter attenuance \(D\)attenuation attenuation coefficient atto attractive potential-energy surface attractive–mixed–repulsive classification attributable risk aufbau principle Auger effect Auger electron Auger electron spectroscopy Auger electron yield Auger yield autacoid auto-ionization autocatalytic reaction automation automerization autophobicity autopoisoning autoprotolysis autoprotolysis constant autoradiograph autoradiolysis auxiliary electrode auxochrome auxotrophy avalanche photodiode average current density average degree of polymerization average life average rate of flow Avogadro constant avoided crossing Avrami equation axial (equatorial) axial chirality axialite axis of chirality axis of helicity aza-di-π-methane rearrangement azacarbenes azamines azanes azenes azides azimines azines azinic acids azlactones azo compounds azo imides azo ylides azomethine imides azomethine oxides azomethine ylides azomethines azonic acids azoxy compounds azylenes α (alpha), β (beta) α-addition α-cleavage α-decay α-effect α-elimination α-oxo carbenes α-particle π-adduct σ-adduct