Gold Book Terms - F

f number f-functional branch point f-functional branch unit fabric filter fac- factor factor-group splitting fall time fallout  in atmospheric chemistryfanning  in atmospheric chemistryfarad faradaic current faradaic current density faradaic demodulation current faradaic rectification current Faraday constant Faraday cup collector fast atom bombardment ionization fast neutrons fast-atom bombardment (FAB) mass spectroscopy fatigue  of a photochromic systemfatty acids feed rate  in catalysisfeed-back inhibition  in biotechnologyfeedback  in analysisfeedback  in kineticsfemto fenestranes Fenton reaction fermentation fermenter fermi Fermi energy Fermi level \(E_{\text{F}}\)fermion feromone ferredoxin ferrimagnetic transition ferrocenophanes ferroelastic transition ferroelectric (antiferroelectric) transition ferroelectric polymer ferroic transition ferromagnetic polymer ferromagnetic transition fertile  in radioanalytical chemistryfibrillar morphology fibrous activated carbon fibrous carbon fibrous crystal in polymers  in polymersfiducial group field desorption  in mass spectrometryfield effect field effect phototransistor field ionization  in mass spectrometryfield level filamentous carbon filler filler coke filling solution  of a reference electrodefilm film badge  in radioanalytical chemistryfilm element film tension filter filter  of a radiationfilter spectrometer filtration fine structure constant \(\alpha\)first-order phase transition first-pass effect Fischer projection Fischer–Rosanoff convention Fischer–Tollens projection fissile  of a materialfission fragment ionization  in mass spectrometryfission fragments fission neutrons fission products fission yield fissionable fixed ions fixed neutral loss (gain) scan  in mass spectrometryfixed neutral loss (gain) spectrum  in mass spectrometryfixed precursor ion scan  in mass spectrometryfixed product ion scan  in mass spectrometryfixed product ion spectrum  in mass spectrometryflagpole flame ionization detector  in gas chromatographyflame photometric detector  in gas chromatographyflame photometry flame-in-tube atomizer  in spectrochemical analysisflammable limits flash fluorimetry flash lamps flash photolysis flash point flash vacuum pyrolysis flat band potential (at a semiconductor/solution interphase) flat bands flavins flavonoids (isoflavonoids and neoflavonoids) flavoproteins flavylium salts floating monolayer floc flocculation floccule Flory–Huggins theory flotation flow analysis flow birefringence flow enthalpimetry flow injection flow injection enthalpimetry flow rate  in chromatographyflow rate  in flame emission and absorption spectrometryflow rate  of a quantityflow rate of unburnt gas mixture  in flame emission and absorption spectrometryflow reactor flow resistance parameter \(\mathit{\Phi}\) in chromatographyflow-programmed chromatography flue gas  in atmospheric chemistryflue gas scrubber  in atmospheric chemistryfluence rate \(E_{\unicode{x26ac}}\)fluence \(F\),\(\varPsi \),\(H_{0}\)fluid coke fluidity \(\phi\)fluidized bed fluoresceins fluorescence fluorescence error  in spectrochemical analysisfluorescence excitation  of X-raysfluorescence lifetime fluorescence resonance energy transfer fluorescence yield fluorimeter fluorocarbons fluorogenic fluorohydrins fluorophore flux depression flux \(J_{\text{X}}\) of a quantityfluxional fly ash  in atmospheric chemistryfoam foam fractionation foaming agent fog fog horizon  in atmospheric chemistryfolates fold domain  in polymer crystalsfold  in polymer crystalsfold plane  in polymer crystalsfold surface  in polymer crystalsfolded-chain crystal  in polymersfoot forbidden line  in X-ray spectroscopyforce constants force-field calculation force \(F\)foreign-gas broadening formamidine disulfides formation constant formazans Förster cycle Förster excitation transfer Förster-resonance-energy transfer forward scattering fossil fuel fouling agent  in catalysisfouling  in membrane processesFourier transform ion cyclotron resonance (FT-ICR) mass spectrometer Fourier transform spectrometer Fourier-transform spectroscopy fractal agglomerate fractal dimension \(d\)fraction fraction collector  in chromatographyfraction extracted \(E\)fractional change of a quantity fractional selectivity  in catalysisfractionation  of analytesfractionation  of polymersfragment ion  in mass spectrometryfragmentation fragmentation reaction  in mass spectrometryframe-shift mutation Franck–Condon principle Franck–Condon state franklin free charge density on the interface free electron laser free energy free radical free rotation free spiro union free-running laser freely draining freely jointed chain  in polymersfreely rotating chain  in polymersfreezing freezing out  in atmospheric chemistryfrequency distribution frequency doubling frequency-domain fluorometry frequency \(f\),\(\nu \)frequency \(\nu\),\(\omega\) in photochemistryFRET friction coefficient friction factor \(\mu\)frictional coefficient \(f\) in polymer chemistryfringed-micelle model  in polymer crystalsfront surface geometry  in luminescencefrontal chromatography frontier orbitals fronting  in chromatographyfrost point hygrometer froth flotation Frumkin effect fucolipid fuel cycle (nuclear) fuel element (nuclear) fuel reprocessing (nuclear) fugacity coefficient \(\phi\)fugacity \(f\),\(\tilde{p}\)fulgides full energy peak fullerenes fulminates fulvalenes fulvenes fume  in atmospheric chemistryfumes fumigation  in atmospheric chemistryfunctional class name functional group functional parent functional polymer functionality \(f\) of a monomerfungicide furanocoumarins furanoses furnace black furnace pyrolysis  in spectrochemical analysisfurocoumarins fusion  in biotechnologyfusion name FWHM (Full Width at Half Maximum)