rel, 1279 relative, 1279 relative activity, 1279 relative adsorption, 1280 relative atomic mass (atomic weight), , 1280 relative biological effectiveness of radiation , 1280 relative configuration, 1280 relative counting in nuclear chemistry , 1281 relative density, , 1281 relative detection limit, 1281 relative electrode potential, 1282 relative elongation, 1282 relative error, 1282 relative hardness, 1282 relative humidity, 1282 relative micellar mass, 1283 relative molar mass, 1283 relative molecular mass, , 1283 relative permeability, , 1283 relative permittivity, , 1283 relative preconcentration in trace analysis , 1284 relative retardation, in planar chromatography , 1284 relative retention, in column chromatography , 1284 relative selectivity in catalysis , 1285 relative spectral responsivity, 1285 relative standard deviation, , , 1285 relative uncertainty, 1285 relative viscosity, 1286 relative viscosity increment, 1286 relative volumic mass, 1286 relativistic effects, 1286 relaxation, 1286 relaxation kinetics, 1287 relaxation time, 1287 releaser in analytical flame spectroscopy , 1287 rem , 1288 Renner–Teller effect, 1288 reorganization energy in electron transfer , 1288 reorganization in polymers , 1289repeatability, 1289 repetency, 1289 replacement name, 1290 replacement operation in organic nomenclature , 1290 replicate (duplicate) sample, 1290 replication, 1290 report in analysis , 1291 reprecipitation, 1291 representative sample, 1291 repression, 1291 reproducibility, 1291 repulsive potential-energy surface, 1292 reserve sample, 1292 residence time, 1292 residence time (hydraulic retention time), in biotechnology , 1293 residual current, 1293 residual emission anisotropy, 1293 residual fuel/oil, 1293 residual liquid junction (potential) error in pH measurement , 1294 residual spectrum/background spectrum in mass spectrometry , 1294 resin, 1294 resist polymer, 1295 resistance, , 1295 resistivity, , 1295 resolution in gas chromatography, 1295 resolution in mass spectroscopy , 1296 resolution in optical spectroscopy, 1296 resolution in stereochemistry , 1296 resolving power in mass spectrometry , 1297 resolving power, in optical spectroscopy , 1297 resolving time correction in nuclear analytical chemistry , 1297 resolving time in nuclear analytical chemistry , 1297 resonance, 1298 resonance absorption technique, 1298 resonance cross-section in Mössbauer spectrometry, 1298 resonance effect magnitude in Mössbauer spectrometry , 1298 resonance energy, 1298 resonance energy in radiochemistry, 1299 resonance fluorescence, 1299 resonance fluorescence technique, 1299