U
- Ugi reactionMulti-component named reaction in organic chemistry
- Ulrich KortzGerman chemist
- Ultimate tensile strengthMaximum stress withstood by stretched material before breaking
- Ultra-high-molecular-weight polyethyleneVery long-chain polyethylene with high impact strength
- Ultrafast laser spectroscopySpectroscopy with lasers with very short pulses
- UltrafiltrationFiltration by force through a semipermeable membrane
- UltramicroscopeType of high-resolution microscope
- Ultratrace elementIn biochemistry, an ultratrace element is a chemical element that normally comprises less
- Ultraviolet–visible spectroscopyRange of spectroscopic analysis
- Uma ChowdhryAmerican chemist
- UN numberUnited Nations code for dangerous substances
- UnbibiumTheoretical chemical element with atomic number 122 (Ubb)
- UnbihexiumTheoretical chemical element with atomic number 126 (Ubh)
- UnbiniliumTheoretical chemical element with atomic number 120 (Ubn)
- UnbiquadiumTheoretical chemical element with atomic number 124 (Ubq)
- UnbiuniumTheoretical chemical element with atomic number 121 (Ubu)
- Unique Ingredient IdentifierFDA identifier in the Global Substance Registration System
- Unit operationBasic step in a process
- Universal indicatorIndicator that works over a wide range of pH
- UnunenniumTheoretical chemical element with atomic number 119 (Uue)
- Upper critical solution temperatureCritical temperature of miscibility in a mixture
- UraniumChemical element with atomic number 92 (U)
- Uranium dioxideChemical compound
- Uranium hexafluorideChemical compound
- Uranium oreEconomically recoverable concentrations of uranium within the Earth's crust
- Uranium-232Isotope of uranium
- Uranium-233Isotope of uranium
- Uranium-234Isotope of uranium
- Uranium-235Isotope of uranium
- Uranium-236Isotope of uranium
- Uranium-238Isotope of uranium
- Uranium–thorium datingUranium–thorium dating, also called thorium-230 dating, uranium-series disequilibrium dati
- UreaOrganic compound
- Urea nitrateUrea nitrate is a fertilizer-based high explosive that has been used in improvised explosi
- Urea perchlorateUrea perchlorate is a sheet-shaped crystallite with good chemical stability and strong hyg
- Urea phosphateUrea phosphate is a 1:1 combination of urea and phosphoric acid that is used as a fertiliz
- Uric acidOrganic compound
- Usama al-KhalidiArab biochemist
- UV detectorsAn ultraviolet detector (also known as UV detector or UV-Vis detector) is a type of non-de