Chemistry, MEI-NIT
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
meitnerium
meitnerium (Mt), an artificially produced element belonging to the transuranium group, atomic number 109. It is......
melamine
melamine, a colourless crystalline substance belonging to the family of heterocyclic organic compounds, which are......
melamine-formaldehyde resin
melamine-formaldehyde resin, any of a class of synthetic resins obtained by chemical combination of melamine (a......
Melanocyte-stimulating hormone
Melanocyte-stimulating hormone (MSH), any of several peptides derived from a protein known as proopiomelanocortin......
Melatonin
Melatonin, hormone secreted by the pineal gland, a tiny endocrine gland situated at the center of the brain. Melatonin......
Meldal, Morten P.
Morten P. Meldal is a Danish chemist whose research into the synthesis of peptides and other organic compounds......
Mendel, Lafayette Benedict
Lafayette Benedict Mendel was an American biochemist whose discoveries concerning the value of vitamins and proteins......
Mendeleev, Dmitri
Dmitri Mendeleev was a Russian chemist who developed the periodic classification of the elements. Mendeleev found......
mendelevium
mendelevium (Md), synthetic chemical element of the actinoid series of the periodic table, atomic number 101. It......
Menten, Maud Leonora
Maud Leonora Menten was a Canadian biochemist and organic chemist best known for her work on enzyme kinetics. She......
menthol
menthol, terpene alcohol with a strong minty, cooling odour and taste. It is obtained from peppermint oil or is......
mercury
mercury (Hg), chemical element, liquid metal of Group 12 (IIb, or zinc group) of the periodic table. atomic number80......
Merrifield, Bruce
Bruce Merrifield was an American biochemist and educator, who in 1984 received the Nobel Prize for Chemistry for......
messenger RNA
messenger RNA (mRNA), molecule in cells that carries codes from the DNA in the nucleus to the sites of protein......
metal
metal, any of a class of substances characterized by high electrical and thermal conductivity as well as by malleability,......
metal carbonyl
metal carbonyl, any coordination or complex compound in which one or more carbon monoxide (CO) molecules are attached......
metalation
metalation, any chemical process by which a metal atom is introduced into an organic molecule to form an organometallic......
Metalloid
Metalloid, in chemistry, an imprecise term used to describe a chemical element that forms a simple substance having......
methane
methane, colourless, odourless gas that occurs abundantly in nature and as a product of certain human activities.......
methanol
methanol (CH3OH), the simplest of a long series of organic compounds called alcohols, consisting of a methyl group......
Methionine
Methionine, sulfur-containing amino acid obtained by the hydrolysis of most common proteins. First isolated from......
methoxychlor
methoxychlor, a largely banned synthetic insecticide. Methoxychlor, a colourless crystalline organic halogen compound,......
methyl bromide
methyl bromide, a colourless, nonflammable, highly toxic gas (readily liquefied) belonging to the family of organic......
methyl chloride
methyl chloride (CH3Cl), a colourless, flammable, toxic gas. Methyl chloride is primarily prepared by reaction......
methyl group
methyl group, one of the commonest structural units of organic compounds, consisting of three hydrogen atoms bonded......
methylene chloride
methylene chloride, a colourless, volatile, practically nonflammable liquid belonging to the family of organic......
Meyer, Lothar
Lothar Meyer was a German chemist who, independently of Dmitry Mendeleyev, developed a periodic classification......
Meyer, Viktor
Viktor Meyer was a German chemist who contributed greatly to knowledge of both organic and inorganic chemistry.......
Meyerhof, Otto
Otto Meyerhof was a German biochemist and corecipient, with Archibald V. Hill, of the 1922 Nobel Prize for Physiology......
Meyerson, Émile
Émile Meyerson was a Polish-born French chemist and philosopher of science whose concepts of rational understanding......
Michaelis-Menten kinetics
Michaelis-Menten kinetics, a general explanation of the velocity and gross mechanism of enzyme-catalyzed reactions.......
Michel, Hartmut
Hartmut Michel is a German biochemist who, along with Johann Deisenhofer and Robert Huber, received the Nobel Prize......
microRNA
microRNA (miRNA), small molecule in cells, typically about 21–25 nucleotides in length, that plays a crucial role......
microscopic reversibility, principle of
principle of microscopic reversibility, principle formulated about 1924 by the American scientist Richard C. Tolman......
Midgley, Thomas, Jr.
Thomas Midgley, Jr. was an American engineer and chemist who discovered the effectiveness of tetraethyl lead as......
misch metal
misch metal, alloy consisting of about 50 percent cerium, 25 percent lanthanum, 15 percent neodymium, and 10 percent......
Mitchell, Peter Dennis
Peter Dennis Mitchell was a British chemist who won the 1978 Nobel Prize for Chemistry for helping to clarify how......
Mitscherlich, Eilhardt
Eilhardt Mitscherlich was a German chemist who promulgated the theory of isomorphism, a relationship between crystalline......
modacrylic
modacrylic, in textiles, any synthetic fibre composed of at least 35 percent but less than 85 percent by weight......
Modrich, Paul
Paul Modrich is an American biochemist who discovered mismatch repair, a mechanism by which cells detect and correct......
Moerner, W.E.
W.E. Moerner is an American chemist who won the 2014 Nobel Prize for Chemistry for his work with single-molecule......
Mohr, Karl Friedrich
Karl Friedrich Mohr was a German chemist who invented such laboratory apparatus as the pinchcock, cork borer, and......
Moissan, Henri
Henri Moissan was a French chemist who received the 1906 Nobel Prize for Chemistry for the isolation of the element......
Mojsov, Svetlana
Svetlana Mojsov is a Yugoslavian-born Macedonian American chemist known for her pioneering contributions to the......
molecular weight
molecular weight, mass of a molecule of a substance, based on 12 as the atomic weight of carbon-12. It is calculated......
molecule
molecule, a group of two or more atoms that form the smallest identifiable unit into which a pure substance can......
Molina, Mario
Mario Molina was a Mexican-born American chemist who was jointly awarded the 1995 Nobel Prize for Chemistry, along......
molybdenum
molybdenum (Mo), chemical element, silver-gray refractory metal of Group 6 (VIb) of the periodic table, used to......
Mond, Ludwig
Ludwig Mond was a German-born British chemist and industrialist who improved the Solvay alkali process and devised......
Monod, Jacques
Jacques Monod was a French biochemist who, with François Jacob, did much to elucidate how genes regulate cell metabolism......
monomer
monomer, a molecule of any of a class of compounds, mostly organic, that can react with other molecules to form......
Monosaccharide
Monosaccharide, any of the basic compounds that serve as the building blocks of carbohydrates. Monosaccharides......
monosodium glutamate
monosodium glutamate (MSG), white crystalline substance, a sodium salt of the amino acid glutamic acid, that is......
Moore, Stanford
Stanford Moore was an American biochemist, who, with Christian B. Anfinsen and William H. Stein, received the 1972......
Morley, Edward Williams
Edward Williams Morley was an American chemist who is best known for his collaboration with the physicist A.A.......
Mosander, Carl Gustaf
Carl Gustaf Mosander was a Swedish chemist whose work revealed the existence of numerous rare-earth elements with......
moscovium
moscovium (Mc), artificially produced transuranium element of atomic number 115. In 2010 scientists at the Joint......
Moseley, Henry
Henry Moseley was an English physicist who experimentally demonstrated that the major properties of an element......
Mulliken, Robert Sanderson
Robert Sanderson Mulliken was an American chemist and physicist who received the 1966 Nobel Prize for Chemistry......
Mullis, Kary
Kary Mullis was an American biochemist, cowinner of the 1993 Nobel Prize for Chemistry for his invention of the......
multiple proportions, law of
law of multiple proportions, statement that when two elements combine with each other to form more than one compound,......
mustard gas
mustard gas, in chemical warfare, a liquid agent that blisters the skin and mucous membranes upon direct contact.......
Mylar
Mylar, (trademark), a versatile plastic film composed of the polyester polyethylene...
Myoglobin
Myoglobin, a protein found in the muscle cells of animals. It functions as an oxygen-storage unit, providing oxygen......
Myosin
Myosin, any of a group of proteins that plays a central role as a molecular motor in cellular movement and force......
Müller, Paul Hermann
Paul Hermann Müller was a Swiss chemist who received the Nobel Prize for Physiology or Medicine in 1948 for discovering......
naphthalene
naphthalene, the simplest of the fused or condensed ring hydrocarbon compounds composed of two benzene rings sharing......
naphthol
naphthol, either of two colourless, crystalline organic compounds derived from naphthalene and belonging to the......
native element
native element, any of a number of chemical elements that may occur in nature uncombined with other elements. The......
Natta, Giulio
Giulio Natta was an Italian chemist who contributed to the development of high polymers useful in the manufacture......
Needham, Joseph
Joseph Needham was an English biochemist, embryologist, and historian of science who wrote and edited the landmark......
Nef, John Ulric
John Ulric Nef was an American chemist whose studies demonstrated that carbon can have a valence (i.e., affinity......
Negishi Ei-ichi
Negishi Ei-ichi was a Japanese chemist who was awarded the 2010 Nobel Prize for Chemistry for his work in using......
neodymium
neodymium (Nd), chemical element, a rare-earth metal of the lanthanide series of the periodic table. Neodymium......
neon
neon (Ne), chemical element, inert gas of Group 18 (noble gases) of the periodic table, used in electric signs......
neoprene
neoprene (CR), synthetic rubber produced by the polymerization (or linking together of single molecules into giant,......
neptunium
neptunium (Np), radioactive chemical element of the actinoid series of the periodic table that was the first transuranium......
Nernst, Walther
Walther Nernst was a German scientist who was one of the founders of modern physical chemistry. His theoretical......
neuraminidase
neuraminidase, any of a group of enzymes that cleave sialic acid, a carbohydrate occurring on the surfaces of cells......
Neurohormone
Neurohormone, any of a group of substances that are produced by specialized neurosecretory cells of the nervous......
neurotransmitter
neurotransmitter, any of a group of chemical agents released by neurons (nerve cells) to stimulate neighbouring......
neurotransmitter release
neurotransmitter release, discharge of chemical substances known as neurotransmitters from a neuron in response......
Newlands, John
John Newlands was an English chemist whose “law of octaves” noted a pattern in the atomic structure of elements......
niacin
niacin, water-soluble vitamin of the B complex. It is also called the pellagra-preventive vitamin because an adequate......
Nicholson, William
William Nicholson was an English chemist, discoverer of the electrolysis of water, which has become a basic process......
nickel
nickel (Ni), chemical element, ferromagnetic metal of Group 10 (VIIIb) of the periodic table, markedly resistant......
nickel–iron
nickel–iron, very rare native alloy of nickel and iron that contains between 24 and 77 percent nickel. It occurs......
nicotine
nicotine, naturally occurring alkaloid produced by tobacco plants and related species. Nicotine is the primary......
Nieuwland, Julius Arthur
Julius Arthur Nieuwland was a Belgian-born American chemist whose studies of acetylene culminated in the discovery......
nihonium
nihonium (Nh), artificially produced transuranium element of atomic number 113. In 2004 scientists at the RIKEN......
niobium
niobium (Nb), chemical element, refractory metal of Group 5 (Vb) of the periodic table, used in alloys, tools and......
Nirenberg, Marshall Warren
Marshall Warren Nirenberg was an American biochemist and corecipient, with Robert William Holley and Har Gobind......
nitrate
nitrate, any member of either of two classes of compounds derived from nitric acid, HNO3. The salts of nitric acid......
nitrate and iodate minerals
nitrate and iodate minerals, small group of naturally occurring inorganic compounds that are practically confined......
nitric acid
nitric acid, (HNO3), colourless, fuming, and highly corrosive liquid (freezing point −42 °C [−44 °F], boiling point......
nitric oxide
nitric oxide (NO), colourless toxic gas that is formed by the oxidation of nitrogen. Nitric oxide performs important......
nitride
nitride, any of a class of chemical compounds in which nitrogen is combined with an element of similar or lower......
nitrile
nitrile, any of a class of organic compounds having molecular structures in which a cyano group (―C ≡ N) is attached......
nitrite
nitrite, any member of either of two classes of compounds derived from nitrous acid. Salts of nitrous acid are......
nitro compound
nitro compound, any of a family of chemical compounds in which the nitro group (―O―N=O) forms part of the molecular......