| σ, π (sigma, pi) |
| σ → σ* transition |
| σ-adduct |
| σ-bond |
| σ-constant |
| σ-orbital |
| S |
| saccharides |
| Sackur–Tetrode constant |
| sacrificial acceptor |
| sacrificial donor |
| sacrificial hyperconjugation |
| saddle point |
| salt |
| salt effect |
| salt form of an ion exchanger |
| salting out |
| sample in analytical chemistry |
| sample error in spectrochemical analysis |
| sample handling in analysis |
| sample injector in chromatography |
| sampler |
| sample unit |
| sampling error |
| sampling interval in electroanalysis |
| sampling plan in analytical chemistry |
| sampling time in electroanalysis |
| sandwich compounds |
| sanitary land fill |
| saprophyte |
| saturated solution |
| saturation |
| saturation in radioanalytical chemistry |
| saturation activity |
| saturation capacity |
saturation fraction,
quantity |
| saturation loading |
| saturation transfer |
| saturation vapour pressure |
| sawhorse projection |
| Saytzeff rule |
| scaler |
| scaling circuit |
| scanning electron microscopy (SEM) |
| scanning method in mass spectrometry |
| scanning transmission electron microscopy (STEM) |
| scattering |
scattering angle,
quantity |
scattering cross-section,
|
| scattering error in spectrochemical analysis |
| scattering matrix |
| scattering plane |
| scattering vector |
| scavenger |
| scavenging |
| Schenck sensitization mechanism |
| Schiff bases (Schiff's bases) |
| Schiller layers |
| Schottky-barrier photodiode |
| Schulze–Hardy rule |
| Schulz–Zimm distribution |
| scintillation |
| scintillation counter |
| scintillation detector |
| scintillation spectrometer |
| scintillators |
| s-cis, s-trans |
| scrambling |
| scrubber in atmospheric chemistry |
| scrubbing |
| seco- |
|
second
unit |
| second of arc |
| second messenger |
| secondary crystallization |
| secondary current distribution |
| secondary electron multiplier in mass spectrometry |
| secondary electrons (se)
in in situ microanalysis |
| secondary electron yield
in in situ microanalysis |
| secondary excitation of X-rays |
| secondary fluorescence
in X-ray emission spectroscopy |
| secondary ionization in mass spectrometry |
| secondary isotope effect |
| secondary kinetic electrolyte effect |
| secondary kinetic isotope effect |
| secondary metabolites |
| secondary pollution (emissions) |
| secondary radiation |
| secondary standard |
| secondary structure |
| second-order transition |
| secular equilibrium |
| sediment |
| sedimentation |
sedimentation coefficient,  quantity |
| sedimentation equilibrium |
| sedimentation field strength |
| sedimentation potential difference (sedimentation
potential)
|
sedimentation velocity,
|
| sedimentation velocity method |
| sedimentation volume |
| segment in analytical chemistry |
| segregated star macromolecule |
| segregation |
| segregation in polymers |
| selected area electron diffraction (SAED) |
| selected ion monitoring in mass spectrometry |
| selection in biotechnology |
| selection rule |
| selective in analysis |
| selective corrosion |
| selective detector |
| selective digestion in spectrochemical analysis |
| selective elution in chromatography |
| selective inhibition in catalysis |
| selectively labelled |
| selective micro-sample in spectrochemical analysis |
| selective poisoning in catalysis |
| selective preconcentration in trace analysis |
| selective sample |
| selective solvent in polymer chemistry |
| selective sorption in polymer chemistry |
| selectivity |
| selectivity in analysis |
| selectivity of a reagent |
selectivity coefficient,
in ion exchange chromatography |
selectivity factor,
quantity |
| selectivity factor
in ion exchange chromatography |
| selectivity ratio |
| selenenic acids |
| selenides |
| seleninic acids |
| selenocyanates |
| selenols |
| selenones |
| selenonic acids |
| selenoxides |
| self-absorption |
| self-absorption broadening of a spectral line |
| self-absorption effect
in luminescence spectroscopy |
| self-absorption factor of a radiation source |
| self-diffusion coefficient |
self inductance,  quantity |
| self-poisoning in catalysis |
| self-quenching |
| self-reversal |
| self-shielding |
| selones |
| semicarbazones |
| semicoke |
| semiconductor |
| semiconductor detector |
| semiconductor laser |
| semiconductor-metal transition |
| semi-interpenetrating polymer network (SIPN) |
| semioxamazones |
| semiquinones |
| semi-rigid chain |
| semisystematic name (semitrivial name) |
| seniority (senior) in organic nomenclature |
| sensitive area of a radiation detector |
| sensitive volume of a radiation detector |
| sensitivity in mass spectrometry |
sensitivity,
in metrology and analytical chemistryquantity |
| sensitization |
| sensitization in colloid chemistry |
| sensitized luminescence |
| sensitizer |
| separability assumption |
| separated flame in flame spectroscopy |
| separation coefficient |
separation factor,
in column chromatographyquantity |
separation factor,
in liquid-liquid distributionquantity |
separation number,
in chromatographyquantity |
| separation temperature in chromatography |
| sequence |
| sequence rules |
| sequencing (proteins, nucleic acids) |
| sequential analyser |
| sequential indication of an analyser |
| sequential measuring cell |
| sequential sample |
| sequential spectrometer |
| series of analytical results |
| serum |
| sesquiterpenoids |
| sesterterpenoids |
| settling chamber in atmospheric chemistry |
| settling error in spectrochemical analysis |
| settling velocity |
| shape selectivity in catalysis |
| shear breakdown |
| shear dependent viscosity |
shear modulus,  quantity |
| shear rate |
shear strain,
quantity |
shear stress,
quantity |
| shear thickening |
| shear thinning |
| shear transition |
| shear viscosity |
| shielded flame in flame spectroscopy |
| shielding |
shielding constant,
quantity |
| shish-kebab structure |
| short chain |
| short-chain branch |
| short-range intramolecular interactions
in polymers |
| shut-down state in analysis |
| shut-down time in analysis |
| shuttle vector |
| SI |
| Si |
| sialon |
| side chain |
| side group |
|
siemens
unit |
|
sievert
unit |
| side group or side-chain polymer liquid crystal |
| sigmatropic rearrangement |
| signal in analysis |
| signal sequence |
| silanes |
| silanols |
| silasesquiazanes |
| silasesquioxanes |
| silasesquithianes |
| silathianes |
| silazanes |
| silicones |
| siloxanes |
| silver film |
| silylene |
| silyl groups |
| silyl radicals |
| simple shear |
| simulation technique in analysis |
| simultaneous nucleation |
| simultaneous pair transitions |
| simultaneous reactions |
| simultaneous spectrometer |
| single-beam (luminescence) spectrometer |
| single cell protein (SCP) |
| single channel pulse height analyser |
| single-electron transfer mechanism (SET) |
| single escape peak |
| single-focusing mass spectrometer |
| single photon counting |
| single photon timing |
| single scattering |
| single-step reaction |
| single-strand chain in a polymer |
| single-strand macromolecule |
| single-strand polymer |
| singlet molecular oxygen |
| singlet-singlet absorption |
| singlet-singlet annihilation |
| singlet-singlet energy transfer |
| singlet state |
| singlet-triplet absorption |
| singlet-triplet energy transfer |
| singly labelled |
| sink in atmospheric chemistry |
| sintering |
| size-exclusion chromatography (SEC) |
| skeletal atom |
| skeletal bond |
| skeletal structure |
| skew |
| Slater-type orbital |
| slot burner |
| slow neutrons |
| small particle in radiation scattering |
| smectic state |
| SM-interference |
| SMILES |
| smog in atmospheric chemistry |
| smog chamber in atmospheric chemistry |
| smog index in atmospheric chemistry |
| smoke |
| smooth transition |
| soap |
| soap curd |
| soap film |
| soft acid |
| soft base |
| soiling in atmospheric chemistry |
| sol |
| solar conversion efficiency |
| solar flare |
| solar radiation in atmospheric chemistry |
| sol-gel transition |
solid angle,
 ,
quantity |
| solidification |
| solid phase antibody radioimmunoassay |
| solid solution |
| solid state lasers |
| solid support in column chromatography |
| solidus |
| solid volume in column chromatography |
| solubility |
solubility parameter,
of a polymerquantity |
| solubility product |
| solubilization |
| solute |
| solute-volatilization interference
in flame spectroscopy |
| solution |
| solvation |
| solvatochromic relationship |
| solvatochromism |
| solvent |
| solvent in liquid-liquid distribution |
| solvent extraction |
| solvent front in chromatography |
| solvent ion exchange (SIX) |
| solvent isotope effect |
| solvent migration-distance in chromatography |
| solvent parameter |
| solvent regeneration in extraction processes |
| solvent-separated ion pair |
| solvent-shared ion pair |
| solvent shift |
| solvolysis |
solvophobicity parameter,
quantity |
| solvus |
| SOMO |
| sonication |
| sonoluminescence |
| soot |
| Soret band |
| sorption in colloid chemistry |
| sorption isotherm in ion exchange |
| sorption techniques in trace analysis |
| sorptive insertion in surface catalysis |
| source efficiency of a radiation source |
| sp |
| space charge in a semiconductor |
| space formula |
| space time in catalysis |
| space velocity in catalysis |
| spacer |
| spark (source) ionization in mass spectrometry |
| spatial-distribution interference
in flame spectroscopy |
| spatially resolving detector of radiation |
| special salt effect |
| speciationreplaced |
| speciation analysis in chemistry |
| speciation in chemistry |
| species (taxonomic) |
| specific |
| specific in analysis |
| specific acid–base catalysis |
specific activity,
in radiochemistryquantity |
| specific adsorption |
| specifically absorbing ion |
| specifically labelled |
| specifically labelled tracer |
| specific burn-up |
| specific catalysis |
| specific conductance |
| specific detector in chromatography |
| specific gravity |
specific heat capacity,
 quantity |
| specific ionization in nuclear chemistry |
| specific permeability in chromatography |
| specific photon emission |
| specific pore volume of a catalyst |
| specific retention volume in chromatography |
| specific surface area in surface chemistry |
specific volume,  quantity |
| specific weight |
| specimen in analytical chemistry |
| spectator mechanism |
| spectator-stripping reaction |
| spectral bandwidth error
in spectrochemical analysis |
| spectral distribution |
| spectral (photon) effectiveness |
| spectral intensity |
| spectral interference in flame spectroscopy |
spectral irradiance,
quantity |
| spectral overlap |
spectral photon exitance,
quantity |
spectral photon flow,
quantity |
spectral photon flux (photon irradiance),
quantity |
spectral photon radiance,
quantity |
| spectral quantities |
spectral radiance,
quantity |
spectral radiant exitance,
quantity |
| spectral radiant flux |
spectral radiant intensity,
quantity |
spectral radiant power,
quantity |
| spectral responsivity |
| spectral responsivity function |
| spectral sensitization |
| spectral spheradiance |
| spectrochemical buffer in atomic spectroscopy |
| spectrochemical carrier in atomic spectroscopy |
| spectrogram |
| spectrograph |
| spectrometer |
| spectrometry |
| spectroscope |
| spectroscopy |
| spectrum analysis |
specular reflectance (reflection factor),
in optical spectroscopyquantity |
speed,
 ,
quantity |
speed distribution function,
 |
| speed of light in a vacuumconstant |
| spherical carbonaceous mesophase |
| spherical radiance |
| spherical radiant exposure |
| spherulite |
| spin adduct |
| spin-allowed electronic transition |
| spin conservation rule (Wigner rule) |
| spin counting |
| spin density |
| spin-flip transition |
| spin-flop transition |
| spin-glass transition |
| spin label |
| spinodal decomposition |
| spin-orbit coupling |
spin-orbit coupling constant,  quantity |
| spin-orbit splitting |
| spin-Peierls transition |
| spin probe |
| spin–spin coupling |
spin–spin coupling constant,
|
| spin-state transition |
| spin trapping |
| spiro atom |
| spiro chain in a polymer |
| spiro compounds |
| spiro macromolecule |
| spiro polymer |
| spiro union |
| splicing |
| spontaneous emission |
| spontaneous fission |
| spontaneous resolution |
| spot in chromatography |
| spot sampling |
| sprayer in flame spectroscopy |
| spreading function in chromatography |
| spreading wetting |
| spread monolayer |
| sputtering |
| sputter yield |
| square-wave current |
| SR |
| stability constant |
| stable |
| stable film, metastable film |
| stable ion in mass spectrometry |
| staggered conformation |
| stagnant inversion in atmospheric chemistry |
| standard acceleration of free fall |
| standard atmosphere |
| standard atomic weights |
| standard chemical potential |
| standard concentration |
| standard conditions for gases |
standard deviation,
|
standard electrode potential,
|
| standard electromotive force |
standard entropy of activation,
 ,
|
standard equilibrium constant,
 ,
|
standard Gibbs energy of activation
 ,
|
| standard hydrogen electrode |
standard molality
 ,
|
| standard potential of an electrode reaction |
| standard potential of the reaction in a chemical
cell
|
| standard pressure |
| standard rate constant of an electrode reaction |
| standard reaction quantities |
| standard solution |
| standard state |
| standard subtraction method
in electroanalytical chemistry |
| standard thermodynamic quantities |
| standard uncertainty |
| stand-by state in analysis |
| stannoxanes |
| stannylenes |
| stannylidenes |
| star copolymer |
| Stark effect |
| star macromolecule |
| star polymer |
| starting line in chromatography |
| starting point in chromatography |
| start-up time in analysis |
| state crossing |
| state diagram |
| state function |
| state-to-state kinetics |
| static fields mass spectrometer |
| static pressure |
| static quenching |
| static stability |
| stationary phase (fermentation) |
| stationary phase in chromatography |
| stationary-phase fraction |
stationary phase volume,
in chromatography |
| stationary state |
| statistical coil in polymers |
| statistical copolymer |
| statistical copolymerization |
| statistical factor |
| statistical pseudo-copolymer |
| statistical segment in polymers |
| statistical weight |
| steady state
in liquid-liquid distribution |
| steady state (stationary state) |
| steady state approximation (treatment) |
| Stefan–Boltzmann constantconstant |
| stem cell |
| stem in polymer crystals |
| step in chromatography |
| step height in chromatography |
| stepped surface |
| stepwise elution in chromatography |
| stepwise reaction |
| steradianunit |
| stereoblock macromolecule |
| stereoblock polymer |
| stereochemical formula (stereoformula) |
| stereoconvergence |
| stereodescriptor |
| stereoelectronic |
| stereoelectronic control |
| stereoformula |
| stereogenic unit (stereogen/stereoelement) |
| stereoheterotopic |
| stereohomosequence in a polymer |
| stereoisomerism |
| stereoisomers |
| stereomutation |
| stereoregular macromolecule |
| stereoregular polymer |
| stereorepeating unit in a polymer |
| stereoselective polymerization |
| stereoselective synthesis |
| stereoselectivity |
| stereosequence in a polymer |
| stereospecifically labelled tracer |
| stereospecificity (stereospecific) |
| stereospecific polymerization |
| steric-approach control |
| steric effect |
| steric factor |
| steric factor in polymers |
| steric hindrance |
| steric isotope effect |
| steric strain |
| Stern layer |
| Stern–Volmer kinetic relationships |
| steroids |
| sterols |
| stibanes |
| stibanylidenes |
| stibines |
| stibinidenes |
| stibonium compounds |
| sticking coefficient in surface chemistry |
| sticking probability in surface chemistry |
| sticky ends in biotechnology |
| stimulated emission |
| stirred flow reactor in catalysis |
| stochastic effect |
| stochastic sampling |
| stochastic theories |
| Stockholm convention |
| Stock number |
| stoichiometric |
| stoichiometric capacity |
stoichiometric concentration,
|
| stoichiometric mean molal (practical activity coefficient)
in electrochemistry |
stoichiometric number,  quantity |
| stoichiometry |
| stokesunit |
| Stokes law |
Stokes number,
quantity |
| Stokes parameters |
| Stokes shift |
| Stokes type radiation |
| stopped flow |
| stopped-flow cell in spectrochemical analysis |
| stopping power |
| STP |
| strain |
| strain-induced transition |
| stratified film |
| stratified sample |
| stratocumulus cloud |
| stratopause |
| stratosphere |
| stratus cloud |
| stray radiation error in spectrochemical analysis |
| streak camera |
| streak tube |
| streaming birefringence |
| streaming current |
| streaming potential difference (streaming potential) |
| stress-assisted transition |
| stress graphitization |
| strip dynode photomultiplier tube |
| stripping |
| stripping isotherm |
| stripping ratio in solvent extraction |
| stripping reaction |
| stripping solution
in liquid-liquid distribution |
| strong collision |
| structural disorder |
| structural formula |
| structural transition |
| structure of a catalyst |
| structure–activity relationship (SAR) |
| structure-based design in drug design |
| structure-property correlations (SPC) |
| styphnates |
| subchain of a polymer |
| subgroup-supergroup transition |
| subjacent orbital |
| sublation in solvent extraction |
| sublimation |
| subphase in thin films |
| subsample |
| substance concentration |
substance content,
|
| substance flow rate |
substance fraction,
quantity |
| substituent atom (group) |
| substituent electronegativity |
| substitution reaction |
| substitutive name |
| substoichiometric extraction |
| substoichiometric isotope dilution analysis |
| substrate |
| substrate in biocatalysis |
| substrate in thin films |
| subtractive name |
| successor complex |
| sudden potential-energy surface |
| sugars |
| suicide inhibition |
| suicide metabolism |
| sulfamic acids |
| sulfanes |
| sulfatides |
| sulfenamides |
| sulfenes |
| sulfenic acids |
| sulfenium ions |
| sulfenyl groups |
| sulfenylium ions |
| sulfenyl nitrenes |
| sulfenyl radicals |
| sulfides |
| sulfilimines |
| sulfimides |
| sulfimines |
| sulfinamides |
| sulfinamidines |
| sulfines |
| sulfinic acids |
| sulfinic anhydrides |
| sulfinimines |
| sulfinylamines |
| sulfolipids |
| sulfonamides |
| sulfonamidines |
| sulfonediimines |
| sulfones |
| sulfonic acids |
| sulfonic anhydrides |
| sulfonimides |
| sulfonium compounds |
| sulfonphthaleins |
| sulfonylamines |
| sulfoxides |
| sulfoximides |
| sulfoximines |
| sulfur diimides |
| sultams |
| sultims |
| sultines |
| sultones |
| summit current in polarography |
| summit potential |
sum of states,
|
| superacid |
| superbase |
| superconducting transition |
| supercritical fluid |
| supercritical fluid chromatography (SFC) |
| superequivalent adsorption |
| superexchange interaction |
| superficial work in surface chemistry |
| superlattice |
| superposability |
| superradiance |
| supersaturation |
| support of a catalyst |
| support-coated open-tubular (SCOT) column
in chromatography |
| supporting electrolyte |
| support plate in chromatography |
| suppressor |
| suprafacial |
| supramolecule |
| surface |
| surface active agent |
surface amount,
 ,
quantity |
| surface barrier semiconductor detector |
| surface catalysis |
surface charge density,
quantity |
| surface charge layer |
| surface chemical potential |
surface concentration,
quantity |
| surface (excess) conductivity |
| surface contamination in surface analysis |
surface coverage,
 quantity |
| surface crossing |
surface density,
 ,
quantity |
| surface dilatational viscosity |
| surface dipole layer |
| surface electric potential |
surface excess,
 quantity |
surface excess concentration (at an interface),
 quantity |
| surface excess energy |
| surface excess enthalpy |
| surface excess entropy |
| surface excess Gibbs energy |
| surface excess Helmholtz energy |
| surface excess isotherm |
| surface ionization in mass spectrometry |
| surface ions |
| surface layer (or interfacial layer) |
| surface of a phase (free surface) |
| surface of tension |
| surface potential |
| surface pressure |
| surface reaction in electrochemistry |
| surface region |
| surface rheology |
| surface shear viscosity |
| surface states |
surface stress,
 |
surface tension,
 ,
quantity |
| surface work |
| surfactant (surface active agent) |
surprisal,
|
| surprisal analysis |
| suspended matter in atmospheric chemistry |
| suspension |
| suspension effect in an ion-selective electrode |
| Swain–Lupton equation |
| Swain–Scott equation |
| swelling in colloid and surface chemistry |
| swelling pressure in colloid and surface chemistry |
| switchboard model in polymer crystals |
| switching transition |
| sydnone imines |
| sydnones |
| sym- |
| symbiosis |
| symbol in quantities and units |
| symmetrical films |
| symmetry-breaking transition |
| symmetry-conserving transition |
symmetry number,
quantity |
| symproportionation |
| syn |
| synartetic acceleration |
| synchronization (principle of nonperfect
synchronization)
|
| synchronous |
| synchronously excited (fluorescence, phosphorescence)
spectrum
|
| synchrotron radiation |
| synclinal |
| syndet |
| syndiotactic macromolecule |
| syndiotactic polymer |
| syndiotactic triads in polymers |
| syneresis |
| synergism in solvent extraction |
| synergism in toxicology |
| synoptic scale |
| synperiplanar |
| syntectic reaction |
| synthetic graphite |
| system |
| systematic error |
| systematic name |
| system of units of measurement |
| Système International d'Unités |
| systemic effect |
| Szilard–Chalmers effect |
