Chemistry, KUH-MCM

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.
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Chemistry Encyclopedia Articles By Title

Kuhn, Richard
Richard Kuhn was a German biochemist who was awarded the 1938 Nobel Prize for Chemistry for work on carotenoids......
Kuhn, Werner
Werner Kuhn was a Swiss physical chemist who developed the first model of the viscosity of polymer solutions using......
Kunckel von Löwenstjern, Johann
Johann Kunckel von Löwenstjern was a German chemist who, about 1678, duplicated Hennig Brand’s isolation of phosphorus.......
Kwolek, Stephanie
Stephanie Kwolek was an American chemist, a pioneer in polymer research whose work yielded Kevlar, an ultrastrong......
Körner, Wilhelm
Wilhelm Körner was a German organic chemist who in 1874 showed how to determine the relative positions of two substituents,......
Lactase
Lactase, enzyme found in the small intestine of mammals that catalyzes the breakdown of lactose (milk sugar) into......
Lactic acid
Lactic acid, an organic compound belonging to the family of carboxylic acids, present in certain plant juices,......
lactone
lactone, any of a class of cyclic organic esters, usually formed by reaction of a carboxylic acid group with a......
Lactose
Lactose, carbohydrate containing one molecule of glucose and one of galactose linked together. Composing about......
Lahav, Meir
Meir Lahav is an Israeli chemist known for his work, conducted in collaboration with Israeli chemist Leslie Leiserowitz,......
Langmuir, Irving
Irving Langmuir was an American physical chemist who was awarded the 1932 Nobel Prize for Chemistry “for his discoveries......
Lanthanide
Lanthanide, any of the series of 15 consecutive chemical elements in the periodic table from lanthanum to lutetium......
lanthanide contraction
lanthanide contraction, in chemistry, the steady decrease in the size of the atoms and ions of the rare-earth elements......
lanthanum
lanthanum (La), chemical element, a rare-earth metal of Group 3 of the periodic table, that is the prototype of......
Laurent, Auguste
Auguste Laurent was a French chemist who helped lay the foundations of organic chemistry. After conventional classical......
Lauterbur, Paul
Paul Lauterbur was an American chemist who, with English physicist Sir Peter Mansfield, won the Nobel Prize for......
Lavoisier, Antoine
Antoine Lavoisier was a prominent French chemist and leading figure in the 18th-century chemical revolution who......
law of reciprocal proportions
law of reciprocal proportions, in chemistry, the statement that if the same weight of one element combines separately......
lawrencium
lawrencium (Lr), synthetic chemical element, the 14th member of the actinoid series of the periodic table, atomic......
Le Bel, Joseph-Achille
Joseph-Achille Le Bel was a French chemist whose explanation of why some organic compounds rotate the plane of......
Le Chatelier, Henry-Louis
Henry-Louis Le Chatelier was a French chemist who is best known for Le Chatelier’s principle, which makes it possible......
lead
lead (Pb), a soft, silvery white or grayish metal in Group 14 (IVa) of the periodic table. Lead is very malleable,......
Lebedev, Sergey Vasilyevich
Sergey Vasilyevich Lebedev was a Russian chemist who developed a method for industrial production of synthetic......
Leblanc, Nicolas
Nicolas Leblanc was a French surgeon and chemist who in 1790 developed the process for making soda ash (sodium......
Lebon, Philippe
Philippe Lebon was a French engineer and chemist, known as the inventor of illuminating gas. While employed as......
Lecithin
Lecithin, any of a group of phospholipids (phosphoglycerides) that are important in cell structure and metabolism.......
Lecoq de Boisbaudran, Paul-Émile
Paul-Émile Lecoq de Boisbaudran was a French chemist who developed improved spectroscopic techniques for chemical......
Lee, Yuan T.
Yuan T. Lee is a Taiwanese-American chemist who, with Dudley R. Herschbach and John C. Polanyi, received the Nobel......
Lefkowitz, Robert J.
Robert J. Lefkowitz is an American physician and molecular biologist who demonstrated the existence of receptors—molecules......
Lehn, Jean-Marie
Jean-Marie Lehn is a French chemist who, together with Charles J. Pedersen and Donald J. Cram, was awarded the......
Leiserowitz, Leslie
Leslie Leiserowitz is an Israeli chemist known for his work, conducted in collaboration with Israeli chemist Meir......
Leloir, Luis Federico
Luis Federico Leloir was an Argentine biochemist who won the Nobel Prize for Chemistry in 1970 for his investigations......
Leslie, Sir John
Sir John Leslie was a Scottish physicist and mathematician who first created artificial ice. In 1802 Leslie’s explanation......
Leucine
Leucine, an amino acid obtainable by the hydrolysis of most common proteins. Among the first of the amino acids......
Levene, Phoebus
Phoebus Levene was a Russian-born American chemist and pioneer in the study of nucleic acids. On receiving an M.D.......
Levitt, Michael
Michael Levitt is an American British Israeli chemist who was awarded the 2013 Nobel Prize for Chemistry for developing......
levodopa
levodopa, Organic compound (L-3,4-dihydroxyphenylalanine) from which the body makes dopamine, a neurotransmitter......
levonorgestrel
levonorgestrel, synthetic progestogen (any progestational steroid, such as progesterone) that is used as a form......
Lewis theory
Lewis theory, generalization concerning acids and bases introduced in 1923 by the U.S. chemist Gilbert N. Lewis,......
Lewis, Gilbert N.
Gilbert N. Lewis was an American physical chemist best known for his contributions to chemical thermodynamics,......
lewisite
lewisite, in chemical warfare, poison blister gas developed by the United States for use during World War I. Chemically,......
Libavius, Andreas
Andreas Libavius was a German chemist, physician, and alchemist who made important chemical discoveries but is......
Libby, Willard Frank
Willard Frank Libby was an American chemist whose technique of carbon-14 (or radiocarbon) dating provided an extremely......
Liebig, Justus, Freiherr von
Justus, baron von Liebig was a German chemist who made significant contributions to the analysis of organic compounds,......
ligand
ligand, in chemistry, any atom or molecule attached to a central atom, usually a metallic element, in a coordination......
ligand field theory
ligand field theory, in chemistry, one of several theories that describe the electronic structure of coordination......
Ligase
Ligase, any one of a class of about 50 enzymes that catalyze reactions involving the conservation of chemical energy......
limonene
limonene, a colourless liquid abundant in the essential oils of pine and citrus trees and used as a lemonlike odorant......
Lindahl, Tomas
Tomas Lindahl is a Swedish biochemist known for his discovery of base excision repair, a major mechanism of DNA......
Lipase
Lipase, any of a group of fat-splitting enzymes found in the blood, gastric juices, pancreatic secretions, intestinal......
Lipmann, Fritz Albert
Fritz Albert Lipmann was a German-born American biochemist, who received (with Sir Hans Krebs) the 1953 Nobel Prize......
Lipoprotein
Lipoprotein, any member of a group of substances containing both lipid (fat) and protein. They occur in both soluble......
Lipscomb, William Nunn, Jr.
William Nunn Lipscomb, Jr. was an American physical chemist who won the Nobel Prize for Chemistry in 1976 for his......
List, Benjamin
Benjamin List is a German chemist who was awarded the 2021 Nobel Prize for Chemistry for his work on asymmetric......
litharge
litharge, one of two mineral forms of lead(II) oxide (PbO). It is found with the other form, massicot, as dull......
lithium
lithium, in pharmacology, drug that is the primary treatment for bipolar disorder. Given primarily in its carbonate......
lithium
lithium (Li), chemical element of Group 1 (Ia) in the periodic table, the alkali metal group, lightest of the solid......
livermorium
livermorium (Lv), artificially produced transuranium element of atomic number 116. In 2000 scientists at the Joint......
Lomonosov, Mikhail
Mikhail Lomonosov was a Russian poet, scientist, and grammarian who is often considered the first great Russian......
London, Fritz Wolfgang
Fritz Wolfgang London was a German American physicist who did pioneering work in quantum chemistry and on macroscopic......
Loschmidt, Joseph
Joseph Loschmidt was a German chemist who made advances in the study of aromatic hydrocarbons. The son of poor......
Louis Pasteur’s Contributions to Science
Many people know Louis Pasteur for the process that bears his name—pasteurization. However, Pasteur made several......
Lovelock, James
James Lovelock was an English chemist, medical doctor, scientific instrument developer, and author best known for......
LSD
LSD, potent synthetic hallucinogenic drug that can be derived from the ergot alkaloids (as ergotamine and ergonovine,......
luciferase
luciferase, enzyme manufactured in the cells of certain organisms to control bioluminescence. The widespread bioluminescence......
Luciferin
Luciferin, in biochemistry, any of several organic compounds whose oxidation in the presence of the enzyme luciferase......
Lucite
Lucite, trademark name of polymethyl methacrylate, a synthetic organic compound of high molecular weight made by......
Luteinizing hormone
Luteinizing hormone (LH), one of two gonadotropic hormones (i.e., hormones concerned with the regulation of the......
lutetium
lutetium (Lu), chemical element, a rare-earth metal of the lanthanide series of the periodic table, that is the......
Lyase
Lyase, in physiology, any member of a class of enzymes that catalyze the addition or removal of the elements of......
lycopene
lycopene, an organic compound belonging to the isoprenoid series and responsible for the red colour of the tomato,......
lye
lye, the alkaline liquor obtained by leaching wood ashes with water, commonly used for washing and in soapmaking;......
Lynen, Feodor
Feodor Lynen was a German biochemist who, for his research on the metabolism of cholesterol and fatty acids, was......
Lysine
Lysine, an amino acid released in the hydrolysis of many common proteins but present in small amounts or lacking......
Lysozyme
Lysozyme, enzyme found in the secretions (tears) of the lacrimal glands of animals and in nasal mucus, gastric......
MacDiarmid, Alan G.
Alan G. MacDiarmid was a New Zealand-born American chemist who, with Alan J. Heeger and Shirakawa Hideki, was awarded......
Macintosh, Charles
Charles Macintosh was a Scottish chemist, best known for his invention in 1823 of a method for making waterproof......
MacKinnon, Roderick
Roderick MacKinnon is an American doctor, corecipient of the Nobel Prize for Chemistry in 2003 for his pioneering......
MacMillan, David W.C.
David W.C. MacMillan is a Scottish-American organic chemist who developed asymmetric organocatalysis, in which......
macromolecule
macromolecule, any very large molecule, usually with a diameter ranging from about 100 to 10,000 angstroms (10−5......
magnesium
magnesium (Mg), chemical element, one of the alkaline-earth metals of Group 2 (IIa) of the periodic table, and......
malathion
malathion, broad-spectrum organophosphate insecticide and acaricide (used to kill ticks and mites). Considerably......
maleic acid
maleic acid, unsaturated organic dibasic acid, used in making polyesters for fibre-reinforced laminated moldings......
malonic acid
malonic acid, (HO2CCH2CO2H), a dibasic organic acid whose diethyl ester is used in syntheses of vitamins B1 and......
Maltase
Maltase, enzyme that catalyzes the hydrolysis of the disaccharide maltose to the simple sugar glucose. The enzyme......
maltose
maltose, organic compound composed of two glucose molecules linked together. The compound (C12H22O11) is a disaccharide......
manganese
manganese (Mn), chemical element, one of the silvery white, hard, brittle metals of Group 7 (VIIb) of the periodic......
Marcus, Rudolph A.
Rudolph A. Marcus is a Canadian-born American chemist, winner of the 1992 Nobel Prize for Chemistry for his work......
Marggraf, Andreas Sigismund
Andreas Sigismund Marggraf was a German chemist whose discovery of beet sugar in 1747 led to the development of......
Marignac, Jean-Charles Galissard de
Jean-Charles Galissard de Marignac was a Swiss chemist whose work with atomic weights suggested the possibility......
Mark, Herman Francis
Herman Francis Mark was an Austrian American chemist who, although not the world’s first polymer chemist, was known......
Markovnikov rule
Markovnikov rule, in organic chemistry, a generalization, formulated by Vladimir Vasilyevich Markovnikov in 1869,......
Markovnikov, Vladimir Vasilyevich
Vladimir Vasilyevich Markovnikov was a Russian organic chemist who contributed to structural theory and to the......
Martin, A.J.P.
A.J.P. Martin was a British biochemist who was awarded (with R.L.M. Synge) the Nobel Prize for Chemistry in 1952......
Marvel, Carl Shipp
Carl Shipp Marvel was an American chemist whose early research was in classic organic chemistry but who is best......
mass action, law of
law of mass action, law stating that the rate of any chemical reaction is proportional to the product of the masses......
massicot
massicot, one of the two forms of lead oxide (PbO) that occurs as a mineral (the other form is litharge). Massicot......
Mayow, John
John Mayow was an English chemist and physiologist who, about a hundred years before Joseph Priestley and Antoine-Laurent......
McMillan, Edwin Mattison
Edwin Mattison McMillan was an American nuclear physicist who shared the Nobel Prize for Chemistry in 1951 with......

Chemistry Encyclopedia Articles By Title