Chemistry, SUL-UNS
How do you use raw plant materials to manufacture a best-selling perfume? How do you engineer household products that are compliant with environmentally-oriented guidelines? The answers to these questions require an understanding of the laws of chemistry, the science that deals with the properties, composition, and structure of elements and compounds, as well as the transformations that such substances undergo and the energy that is released or absorbed during those processes. Chemistry is also concerned with the utilization of natural substances and the creation of artificial ones. Over time, more than 8,000,000 different chemical substances, both natural and artificial, have been characterized and produced. Chemistry's vast scope comprises organic, inorganic, physical, analytical, and industrial chemistry, along with biochemistry, environmental chemistry, medicinal chemistry, and much more. Through the dedicated efforts of people such as Robert Boyle, Dmitri Mendeleev, John Dalton, Marie Curie, and Rosalind Franklin, the field of chemistry has led to exciting innovations as well as crucial advances in our understanding of how the world functions, starting with the miniscule and unassuming atom.
Chemistry Encyclopedia Articles By Title
sulfuric acid
sulfuric acid (H2SO4), colorless, odorless, oily, and corrosive liquid that is a widely manufactured industrial......
Sumner, James Batcheller
James Batcheller Sumner was an American biochemist and corecipient, with John Howard Northrop and Wendell Meredith......
superheated steam
superheated steam, water vapour at a temperature higher than the boiling point of water at a particular pressure.......
surface analysis
surface analysis, in analytical chemistry, the study of that part of a solid that is in contact with a gas or a......
Suzuki Akira
Suzuki Akira is a Japanese chemist who was awarded the 2010 Nobel Prize for Chemistry for his work in using palladium......
Svedberg, Theodor H.E.
Theodor H.E. Svedberg was a Swedish chemist who won the Nobel Prize for Chemistry in 1926 for his studies in the......
Swan, Joseph
Joseph Swan was an English physicist and chemist who produced an early electric lightbulb and invented the dry......
Sylvius, Franciscus
Franciscus Sylvius was a physician, physiologist, anatomist, and chemist who is considered the founder of the 17th-century......
Synge, R.L.M.
R.L.M. Synge was a British biochemist who in 1952 shared the Nobel Prize for Chemistry with A.J.P. Martin for their......
Szent-Györgyi, Albert
Albert Szent-Györgyi was a Hungarian biochemist whose discoveries concerning the roles played by certain organic......
Szostak, Jack W.
Jack W. Szostak is an English-born American biochemist and geneticist who was awarded the 2009 Nobel Prize for......
Taenite
Taenite, nickel-iron mineral having a face-centred cubic structure and playing a major role in the crystallization......
Takamine, Jokichi
Jokichi Takamine was a biochemist and industrial leader whose most important achievement was the isolation of the......
Talbot, William Henry Fox
William Henry Fox Talbot was an English chemist, linguist, archaeologist, and pioneer photographer. He is best......
Tammann, Gustav
Gustav Tammann was a Russian chemist who helped to found the science of metallurgy and pioneered in the study of......
Tanaka Koichi
Tanaka Koichi is a Japanese scientist who, with John B. Fenn and Kurt Wüthrich, won the Nobel Prize for Chemistry......
tantalum
tantalum (Ta), chemical element, bright, very hard, silver-gray metal of Group 5 (Vb) of the periodic table, characterized......
tartaric acid
tartaric acid, a dicarboxylic acid, one of the most widely distributed of plant acids, with a number of food and......
Tatum, Edward L.
Edward L. Tatum was an American biochemist who helped demonstrate that genes determine the structure of particular......
Taube, Henry
Henry Taube was a Canadian-born American chemist, who won the Nobel Prize for Chemistry in 1983 for his extensive......
taxol
taxol, organic compound with a complex multi-ring molecule that occurs in the bark of Pacific yew trees (Taxus......
tear gas
tear gas, any of a group of substances that irritate the mucous membranes of the eyes, causing a stinging sensation......
technetium
technetium (Tc), chemical element, synthetic radioactive metal of Group 7 (VIIb) of the periodic table, the first......
Telkes, Mária
Mária Telkes was a Hungarian-born American physical chemist and biophysicist best known for her invention of the......
tellurium
tellurium (Te), semimetallic chemical element in the oxygen group (Group 16 [VIa] of the periodic table), closely......
Telomerase
Telomerase, enzyme that influences cell life span by adding organic compounds known as nucleotides to telomeres,......
tennessine
tennessine (Ts), artificially produced transuranium element of atomic number 117. In 2010 Russian and American......
terbium
terbium (Tb), chemical element, a rare-earth metal of the lanthanide series of the periodic table. Terbium is a......
terpene
terpene, any of a class of hydrocarbons occurring widely in plants and animals and empirically regarded as built......
Testosterone
Testosterone, hormone produced by the male testis that is responsible for development of the male sex organs and......
tetrachloroethane
tetrachloroethane, either of two isomeric colourless, dense, water-insoluble liquids belonging to the family of......
tetrachloroethylene
tetrachloroethylene, a colorless, dense, nonflammable, highly stable liquid belonging to the family of organic......
tetraethyl lead
tetraethyl lead (TEL), organometallic compound containing the toxic metal lead that for much of the 20th century......
tetraethyl pyrophosphate
tetraethyl pyrophosphate, an organic phosphorus compound used as an insecticide, particularly for the control of......
tetrafluoroethylene
tetrafluoroethylene, a colourless, odourless, faintly toxic gas belonging to the family of organic halogen compounds;......
tetrahydrocannabinol
tetrahydrocannabinol (THC), active constituent of marijuana and hashish that was first isolated from the marijuana......
thallium
thallium (Tl), chemical element, metal of main Group 13 (IIIa, or boron group) of the periodic table, poisonous......
Thenard, Louis-Jacques
Louis-Jacques Thenard was a French chemist, teacher, and author of an influential four-volume text on basic chemical......
theobromine
theobromine, diuretic drug and major alkaloidal constituent of cocoa. Theobromine is a xanthine alkaloid, a methylxanthine,......
theophylline
theophylline, alkaloidal drug used in medicine as an antiasthmatic, coronary vasodilator, and diuretic. Theophylline......
Theorell, Axel Hugo Teodor
Axel Hugo Teodor Theorell was a Swedish biochemist whose study of enzymes that facilitate oxidation reactions in......
thiamin
thiamin, water-soluble organic compound that is necessary for carbohydrate metabolism in both plants and animals.......
thiazine
thiazine, any of three organic compounds of the heterocyclic series, having molecular structures that include a......
thiazole
thiazole, any of a class of organic compounds of the heterocyclic series characterized by a ring structure composed......
thimerosal
thimerosal, mercury-containing organic compound with antimicrobial and preservative properties. Thimerosal was......
thiol
thiol, any of a class of organic chemical compounds similar to the alcohols and phenols but containing a sulfur......
thiophene
thiophene, the simplest sulfur-containing aromatic compound, with molecular formula C4H4S, which closely resembles......
thiourea
thiourea, an organic compound that resembles urea (q.v.) but contains sulfur instead of oxygen; i.e., the molecular......
Thomsen, Julius
Julius Thomsen was a Danish chemist who determined the amount of heat evolved from or absorbed in a large number......
Thoracotropic hormone
Thoracotropic hormone, neurohormone secreted in arthropods. After being released by neurosecretory cells of the......
thorium
thorium (Th), radioactive chemical element of the actinoid series of the periodic table, atomic number 90; it is......
thorium series
thorium series, set of unstable heavy nuclei comprising one of the four radioactive...
Thorpe, Sir Thomas Edward
Sir Thomas Edward Thorpe was a chemist and director of British government laboratories (1894–1909) who, with a......
Threonine
Threonine, an amino acid obtainable from many proteins. One of the last amino acids to be isolated (1935), threonine......
thulium
thulium (Tm), chemical element, a rare-earth metal of the lanthanide series of the periodic table. Thulium is a......
Thymine
Thymine, organic compound of the pyrimidine family that is a constituent of deoxyribonucleic acid (DNA). DNA, along......
Thyrotropin
Thyrotropin, substance produced by cells called thyrotrophs in the anterior pituitary gland. Thyrotropin binds......
thyrotropin-releasing hormone
thyrotropin-releasing hormone, simplest of the hypothalamic neurohormones, consisting of three amino acids in the......
Thyroxine
Thyroxine, one of the two major hormones secreted by the thyroid gland (the other is triiodothyronine). Thyroxine’s......
tin
tin (Sn), a chemical element belonging to the carbon family, Group 14 (IVa) of the periodic table. It is a soft,......
Tiselius, Arne
Arne Tiselius was a Swedish biochemist who won the Nobel Prize for Chemistry in 1948 for his work on electrophoresis......
titanium
titanium (Ti), chemical element, a silvery gray metal of Group 4 (IVb) of the periodic table. Titanium is a lightweight,......
titanium dioxide
titanium dioxide, (TiO2), a white, opaque, naturally occurring mineral existing in a number of crystalline forms,......
Today in History—April 19: The Very First Acid Trip in History
On this day in 1943, Swiss research chemist Albert Hofmann conducted an outlandish experiment—on himself. He dosed......
Today in History—March 6: The Introduction of the Periodic Table
On this day in 1869, Russian chemist Dmitri Mendeleev took a break from improving cheese-making techniques to show......
Today in History—October 15: Putting the Power of Birth Control in a Pill
On October 15, 1951, Luis E. Miramontes, a chemist working in Mexico City at the pharmaceutical company Syntex,......
Todd (of Trumpington), Alexander Robertus Todd, Baron
Alexander Robertus Todd, Baron Todd was a British biochemist whose research on the structure and synthesis of nucleotides,......
tolbutamide
tolbutamide, drug used in the treatment of type II (non-insulin-dependent) diabetes. Tolbutamide stimulates the......
Tolman, Richard C
Richard C. Tolman was a U.S. physical chemist and physicist who demonstrated the electron to be the charge-carrying......
toluene
toluene, aromatic hydrocarbon used extensively as starting material for the manufacture of industrial chemicals.......
Torrey, John
John Torrey was a botanist and chemist known for his extensive studies of North American flora. Torrey was educated......
toxin
toxin, any substance poisonous to an organism. The term is sometimes restricted to poisons spontaneously produced......
Transaminase
Transaminase, any of a group of enzymes that catalyze the transfer of the amino group (―NH2) of an amino acid to......
transcription factor
transcription factor, molecule that controls the activity of a gene by determining whether the gene’s DNA (deoxyribonucleic......
transfer RNA
transfer RNA (tRNA), small molecule in cells that carries amino acids to organelles called ribosomes, where they......
Transferase
Transferase, any one of a class of more than 450 enzymes that catalyze the transfer of various chemical groups......
transferrin
transferrin, protein (beta1 globulin) in blood plasma that transports iron from the tissues and bloodstream to......
transition metal
transition metal, any of various chemical elements that have valence electrons—i.e., electrons that can participate......
transition-state theory
transition-state theory, treatment of chemical reactions and other processes that regards them as proceeding by......
transuranium element
transuranium element, any of the chemical elements that lie beyond uranium in the periodic table—i.e., those with......
Traube, Isidor
Isidor Traube was a German physical chemist who founded capillary chemistry and whose research on liquids advanced......
triad
triad, in chemistry, any of several sets of three chemically similar elements, the atomic weight of one of which......
tributyl phosphate
tributyl phosphate, an organic liquid solvent used in the extraction of uranium and plutonium salts from reactor......
trichloroethane
trichloroethane, either of two isomeric colourless, nonflammable liquids belonging to the family of halogenated......
trichloroethylene
trichloroethylene, a colourless, toxic, volatile liquid belonging to the family of organic halogen compounds, nonflammable......
Triglyceride
Triglyceride, any one of an important group of naturally occurring lipids (fat-soluble components of living cells).......
trinitrotoluene
trinitrotoluene (TNT), a pale yellow, solid organic nitrogen compound used chiefly as an explosive, prepared by......
tritium
tritium, (T, or 3H), the isotope of hydrogen with atomic weight of approximately 3. Its nucleus, consisting of......
triton
triton, nucleus of the heaviest hydrogen isotope, tritium, or hydrogen-3. Tritons, which consist of one proton......
Tryptophan
Tryptophan, an amino acid that is nutritionally important and occurs in small amounts in proteins. It is an essential......
Tsien, Roger Y.
Roger Y. Tsien was an American chemist who was a corecipient, with Osamu Shimomura and Martin Chalfie, of the 2008......
Tu Youyou
Tu Youyou is a Chinese scientist and phytochemist known for her isolation and study of the antimalarial substance......
Tumour necrosis factor
Tumour necrosis factor (TNF), a naturally occurring protein that is produced in the human body by the phagocytic......
tungsten
tungsten (W), chemical element, an exceptionally strong refractory metal of Group 6 (VIb) of the periodic table,......
tungsten carbide
tungsten carbide, an important member of the class of inorganic compounds of carbon, used alone or with 6 to 20......
Tyrian purple
Tyrian purple, naturally occurring dye highly valued in antiquity. It is closely related to indigo...
Tyrosine
Tyrosine, an amino acid comprising about 1 to 6 percent by weight of the mixture obtained by hydrolysis of most......
Ubiquinone
Ubiquinone, any of several members of a series of organic compounds belonging to a class called quinones. Widely......
unsaturated fat
unsaturated fat, a fatty acid in which the hydrocarbon molecules have two carbons that share double or triple bond(s)......
unsaturated polyester
unsaturated polyester, any of a group of thermosetting resins produced by dissolving a low-molecular-weight unsaturated......