Chemistry
Articles about matter, substances, reactions and chemical science.
Toothpaste
Toothpaste: purpose, composition, varieties, history, and safety
Torquoselectivity
Torquoselectivity in electrocyclic reactions
Toxaphene
Toxaphene (camphechlor): persistent insecticide and environmental pollutant
Toxic metals
Toxic metals: causes, health effects, exposure and prevention
Toxicity
Toxicity: how substances harm organisms and how toxicology measures risk
Trace element
Transactinide element
Transactinide elements
Transition metal
Transition metals: d‑block elements — properties, classification, and applications
Transition state
Transition state (chemistry)
Transmutation
Transuranium element
Transuranium element: elements beyond uranium in the periodic table
Triclinic
Triclinic crystal system
Trifluoromethylphenylpiperazine
Trifluoromethylphenylpiperazine (TFMPP) — overview and context
Triglyceride
Triglyceride (triacylglycerol): structure, role, and significance
Trinitrotoluene
Trinitrotoluene (TNT)
Triple point
Tritium
Tungsten
Tungsten (W) — Properties, Uses, and History
Turpentine
Tyrosine
Ultramarine
Ultramarine (deep blue pigment and colour)
Ultraviolet–visible absorption
Unbinilium
Unbinilium (element 120)
Unbioctium
Unbioctium (element 128) — proposed superheavy element
Unbipentium
Unbipentium (Ubp) — hypothetical element with atomic number 125
Unbiunium
Universal indicator
Universal indicator: composition, uses, and limitations
Ununennium
Ununennium (Element 119): predicted properties, synthesis attempts, and significance
Uranium
Uranium: properties, isotopes, uses, history, and safety
Comprehensive overview of uranium: its physical and nuclear properties, principal isotopes, geological occurrence, uses in energy and weapons, historical discovery, and health and
Uranium trioxide
Uranium trioxide (UO3) — properties, production, uses, and hazards
Uranium-235
Uranium-235: fissile isotope used in reactors and weapons
Uranyl nitrate
Urea
Urea (carbamide): chemistry, biological role, uses and history
Uric acid
Uric acid: chemistry, biology, and clinical significance
Valence
Valence (chemistry, linguistics, and psychology)
Valence electron
Valency
Valency (valence) in chemistry: definition, history, and distinctions
Valentinite
Van der Waals force
Van der Waals force: weak intermolecular attractions and their roles
Van der Waals forces are weak, short-range noncovalent interactions between atoms and molecules — including dispersion, dipole and induced-dipole effects — important in chemistry,
Van der Waals radius
Vanadium
Vanadium: properties, occurrence, chemistry, uses and biological roles
Vapor
Vapor (vapour): definition, formation, uses and distinctions
Varnish
Vitamin A
Vitamin A: forms, functions, dietary sources, deficiency and safety