Chemistry

Tellurous acid (H2TeO3): properties, structure, and uses Tellurous acid Tellurous acid (H2TeO3) is a weak, diprotic oxyacid of tellurium in oxidation state +4. It exists mainly in aqueous solution, forms tellurite salts, and has limited practical uses;…

Tennessine (element 117) Tennessine Tennessine (Ts, atomic number 117) is a synthetic, radioactive superheavy element in group 17. It was synthesized in 2010 by a Russian–U.S. collaboration and exists only as short-l…

Terbium (Tb): properties, history, and practical uses Terbium Terbium is a silvery rare-earth metal (symbol Tb, atomic number 65) used in phosphors, magnetostrictive alloys and electronic materials. This article covers its properties, origin,…

Test tube (laboratory glassware) Test tube Open-ended cylindrical tubes used in laboratories to hold, heat, mix, and store small samples; made in various sizes and materials (glass or plastic) and available in specialized f…

Tetrahydrocannabinol (THC): Overview, Chemistry, Effects, and Uses Tetrahydrocannabinol Tetrahydrocannabinol (THC) is the primary psychoactive compound in cannabis. This entry explains its chemistry, biological effects, plant role, medical and recreational uses, and l…

Tetraoxygen (O4) Tetraoxygen Tetraoxygen, O4 (sometimes called oxozone), is a short‑lived or pressure‑stabilized form of oxygen studied in laboratory experiments and high‑pressure physics; it appears as dimers…

Tetrasulfur tetranitride (S4N4): structure, properties and reactivity Tetrasulfur tetranitride Tetrasulfur tetranitride (S4N4) overview: structure, bonding, synthesis, reactivity, hazards, and role as precursor to polymeric sulfur nitrides and related materials.

Thallium — properties, occurrence, uses and toxicity Thallium Thallium (Tl, atomic number 81) is a soft, silvery post‑transition metal. It occurs as a trace byproduct of sulfide ore processing, has specialized industrial and medical uses, and…

Thallium halides Thallium halide Compounds of thallium with halogens, including monohalides (Tl+ dominant) and trihalides (Tl3+), covering structures, chemistry, uses and safety considerations.

Thallium(I) bromide (TlBr) Thallium(I) bromide Thallium(I) bromide, TlBr, is an ionic thallium halide used in optics and radiation detection; it forms a crystalline solid containing Tl+ and Br− and must be handled as a toxic ma…

Thallium(I) carbonate (Tl2CO3) Thallium(I) carbonate Thallium(I) carbonate (Tl2CO3) is an ionic salt of thallium in the +1 oxidation state and carbonate anions. It is used in research and synthesis and is highly toxic; handled under…

Thallium(I) chloride (TlCl): properties, preparation, uses and safety Thallium(I) chloride Thallium(I) chloride (TlCl) is an ionic thallium salt commonly encountered as a colorless, sparingly soluble solid. It is used mainly in research; like all thallium compounds it is…

Thallium(I) fluoride (TlF) Thallium(I) fluoride Thallium(I) fluoride, TlF, is a binary inorganic salt of thallium and fluoride. It is a colorless ionic solid used mainly in research and synthesis; like other thallium salts it is…

Thallium(I) hydroxide (TlOH) Thallium(I) hydroxide Thallium(I) hydroxide, TlOH, is the +1 thallium salt of hydroxide. A strong base used chiefly in research and synthesis; chemically similar to alkali hydroxides and highly toxic.

Thallium(I) iodide (thallous iodide) Thallium(I) iodide Thallium(I) iodide (TlI) is an inorganic compound of thallium in the +1 state and iodide. A colored, sparingly soluble crystalline solid, it is used in research and some light-emit…

Thallium(I) oxide (thallous oxide): properties, preparation, uses Thallium(I) oxide Thallium(I) oxide (Tl2O) is an inorganic salt containing Tl+ and O2−. Overview of composition, behavior, preparation routes, applications, and toxicity precautions for this thalliu…

Thallium(I) sulfate (thallous sulfate) Thallium(I) sulfate Thallium(I) sulfate (Tl2SO4) is a colorless, water-soluble inorganic salt of thallium and sulfate. It is highly toxic, historically used as a rodenticide, and now tightly regulated…

Thallium(I) sulfide (Tl2S) Thallium(I) sulfide Thallium(I) sulfide, Tl2S, is an inorganic thallium salt of sulfide. This article summarizes composition, properties, synthesis, uses, hazards, and historical context.

Thallium(III) hydroxide (Tl(OH)3) Thallium(III) hydroxide An inorganic compound of thallium in the +3 oxidation state. Tl(OH)3 is a trivalent metal hydroxide that is relatively unstable and handled mainly in research under strict safety c…

Thallium(III) oxide (Tl2O3): properties, preparation and safety Thallium(III) oxide Thallium(III) oxide (Tl2O3) is an inorganic thallium oxide containing Tl3+ and oxide ions. It is mainly of research interest and is handled with caution because thallium compounds…

The Chemical Brothers British electronic music duo known for pioneering big beat, bold live shows, sample-rich production and chart-topping albums; formed in Manchester and influential since the 1990s.

The Sceptical Chymist — Robert Boyle's foundational work in chemistry The Sceptical Chymist A concise account of Robert Boyle's 1661 book The Sceptical Chymist, its arguments against classical doctrines, its method, and its lasting role in the emergence of modern chemistr…

Theobromine: chemistry, occurrence, effects, history, and safety Theobromine An encyclopedic overview of theobromine — a naturally occurring dimethylxanthine in cacao and chocolate, its chemistry, biological effects, historical isolation, uses, and toxicity…

Theoretical chemistry: principles, methods, and applications Theoretical chemistry An introduction to theoretical chemistry: its aims, main tools (quantum chemistry, statistical mechanics, molecular modeling), historical development, typical applications, and lim…

Thermal decomposition Thermal decomposition is the heat-driven breakdown of chemical compounds into simpler substances. This entry explains mechanisms, controlling factors, historical context, common ex…

Thermite and aluminothermic reactions Thermite Thermite is a pyrotechnic composition of a metal oxide and a reactive metal that produces intense local heat by aluminothermic or similar redox reactions, used for welding, cutting…

Thermochemistry: energy and heat in chemical reactions and phase changes Thermochemistry Thermochemistry examines heat and energy changes during chemical reactions and physical changes. It explains enthalpy, entropy, calorimetry and applications in engineering, materia…

Thermoplastic Thermoplastics are polymers that soften when heated and harden when cooled, allowing repeated reshaping. They are widely used in manufacturing, packaging, electronics and consumer…

Thermosetting Polymer (Thermoset): Properties, Processing and Uses Thermosetting polymer Overview of thermosetting polymers: chemistry, curing methods, common types, processing, applications, comparison with thermoplastics, recycling challenges and safety consideration…

Thial (thioaldehyde): structure, reactivity, synthesis and uses Thial Thials (thioaldehydes) are carbon–sulfur analogues of aldehydes (RC(S)H). They are highly reactive electrophiles used transiently in synthesis and studied for their distinctive bon…

Thin-layer chromatography (TLC): principles, procedure, and applications Thin layer chromatography Thin-layer chromatography (TLC) is a rapid, planar chromatographic technique using a thin adsorbent layer on an inert support to separate, identify, and sometimes purify components…

Thioester Thioesters are organic compounds in which a sulfur atom replaces the ester oxygen; they are reactive acyl derivatives with important roles in chemistry and metabolism.

Thioether (sulfide): structure, properties, and uses Thioether A thioether (sulfide) is an organic compound with an R–S–R linkage. This article explains its structure, chemical behavior, natural occurrence, common preparations and industrial a…

Thioketone (thione): the sulfur analogues of ketones Thioketone Thioketones (thiones) are organic compounds with a C=S group. This article explains their structure, bonding, reactivity, synthesis, examples and how they differ from ordinary keto…

Thiol (mercaptan): structure, properties, reactions, and uses Thiol Thiol (R–SH) compounds: sulfur-containing analogues of alcohols. Overview of structure, physical and chemical properties, common reactions, uses (odorants, synthesis) and biologica…

Thistle tube (thistle funnel) — laboratory glassware Thistle tube A thistle tube, or thistle funnel, is a simple glass instrument for adding liquids into vessels or closed apparatus by gravity. Common in teaching and research labs for coarse, loc…

Thixotropy: time-dependent shear thinning in gels and fluids Thixotropy Thixotropy is a reversible, time-dependent decrease in viscosity that occurs in some gels and fluids when they are mechanically disturbed, important in paints, foods, cosmetics, an…

Thorium: a silvery actinide with potential as a nuclear fuel Thorium Thorium (Th, Z=90) is a weakly radioactive, silvery actinide metal found in several minerals. It has industrial uses and a distinct nuclear fuel cycle with potential advantages and…

Thulium — properties, history, and applications of element Tm Thulium Thulium (Tm, atomic number 69) is a rare-earth lanthanide metal known for its use in near- and mid-infrared lasers, a single stable isotope, and limited commercial availability.

Thymine (5‑methyluracil): the DNA pyrimidine base Thymine Thymine, or 5‑methyluracil, is a pyrimidine nucleobase found in DNA that pairs with adenine and contributes to genetic stability and recognition during replication and repair.

Tin (chemical element) Tin Tin is a silvery metal (symbol Sn, atomic number 50) used in alloys, solder and coatings. It has distinctive allotropes, a long history from the Bronze Age, and modern roles in ele…

Tin oxide (SnO and SnO₂): properties, structures, uses, and distinctions Tin oxide Overview of the two principal tin oxides — tin(II) oxide (SnO) and tin(IV) oxide (SnO₂) — covering structure, chemistry, production, applications (coatings, sensors, polishing, bat…

Tin(II) bromide (stannous bromide) — SnBr2 Tin(II) bromide Tin(II) bromide (SnBr2) is a stannous halide: a pale crystalline solid containing tin in the +2 oxidation state. It is used as a reducing agent, reagent precursor and in materials…

Tin(II) chloride (stannous chloride) Tin(II) chloride Tin(II) chloride (SnCl2), commonly called stannous chloride, is a tin salt and mild reducing agent used in synthesis, plating, and analytical chemistry; it exists as hydrates and i…

Tin(II) fluoride (stannous fluoride) Tin(II) fluoride Tin(II) fluoride (SnF2), commonly called stannous fluoride, is a tin salt used mainly in dental products to prevent cavities and has applications in chemistry and industry.

Tin(II) iodide (stannous iodide) Tin(II) iodide An overview of tin(II) iodide (SnI2): composition, properties, preparation, uses, structure and safety notes for this tin(II) halide.

Tin(II) oxide (stannous oxide) Tin(II) oxide Tin(II) oxide (SnO) is a compound of tin in the +2 oxidation state. It is an amphoteric, p-type semiconducting oxide used in glass, ceramics and as a precursor to tin salts.

Tin(II) sulfate (stannous sulfate) Tin(II) sulfate Inorganic salt SnSO4, a tin(II) sulfate compound used as a source of Sn2+ in chemistry and electroplating; properties, preparation, uses, and safety summarized.