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James Walker (chemist)
Sir James Walker FRS FRSE FCS LLD (6 April 1863 – 6 May 1935) was a Scottish chemist. Life He was born at Logie House, in north-west Dundee the son of James Walker of J & H Walker, jute and flax spinners and weavers, and owners of the Dura Works. His mother was Susan Hutchison Cairns. He was educated at the High School of Dundee, and, although he had passed the entrance examination for the University of St Andrews, he instead joined his father's company. He stayed there for three years, then entered the University of Edinburgh to study sciences in 1882. He graduated with a BSc in 1885 and gained a doctorate in 1886. He then spent three years in Germany, working with Ludwig Claisen, Adolf von Baeyer and Wilhelm Ostwald. Following a PhD at the University of Leipzig in 1889, he returned to Britain, working in Edinburgh and University College, London, before being appointed professor of chemistry at the University College, Dundee in 1894. In 1890 he was elected a Fell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fellow Of The Royal Society
Fellowship of the Royal Society (FRS, ForMemRS and HonFRS) is an award granted by the judges of the Royal Society of London to individuals who have made a "substantial contribution to the improvement of natural science, natural knowledge, including mathematics, engineering science, and medical science". Fellow, Fellowship of the Society, the oldest known scientific academy in continuous existence, is a significant honour. It has been awarded to many eminent scientists throughout history, including Isaac Newton (1672), Michael Faraday (1824), Charles Darwin (1839), Ernest Rutherford (1903), Srinivasa Ramanujan (1918), Albert Einstein (1921), Paul Dirac (1930), Winston Churchill (1941), Subrahmanyan Chandrasekhar (1944), Dorothy Hodgkin (1947), Alan Turing (1951), Lise Meitner (1955) and Francis Crick (1959). More recently, fellowship has been awarded to Stephen Hawking (1974), David Attenborough (1983), Tim Hunt (1991), Elizabeth Blackburn (1992), Tim Berners-Lee (2001), Venki R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexander Crum Brown
Alexander Crum Brown FRSE FRS (26 March 1838 – 28 October 1922) was a Scottish organic chemist. Alexander Crum Brown Road in Edinburgh's King's Buildings complex is named after him. Early life and education Crum Brown was born at 4 Bellevue Terrace in Edinburgh. His mother, Margaret Fisher Crum (d.1841), was the sister of the chemist Walter Crum, and his father, Rev Dr John Brown (1784-1858), was minister of Broughton Place Church in the east end of Edinburgh's New Town. His half brother was the physician and essayist John Brown. For five years he studied at the Royal High School, then for one year at Mill Hill School in London. In 1854, he entered the University of Edinburgh where he first studied Arts and then Medicine. He was gold medallist in Chemistry and Natural Philosophy and graduated with an MA in 1858. Continuing his medical studies, he received his MD in 1861. At this time he was also studying for a science degree at the University of London, and in 1862 became ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
First World War
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fighting occurring throughout Europe, the Middle East, Africa, the Pacific, and parts of Asia. An estimated 9 million soldiers were killed in combat, plus another 23 million wounded, while 5 million civilians died as a result of military action, hunger, and disease. Millions more died in genocides within the Ottoman Empire and in the 1918 influenza pandemic, which was exacerbated by the movement of combatants during the war. Prior to 1914, the European great powers were divided between the Triple Entente (comprising France, Russia, and Britain) and the Triple Alliance (containing Germany, Austria-Hungary, and Italy). Tensions in the Balkans came to a head on 28 June 1914, following the assassination of Archduke Franz Ferdina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Davy Medal
The Davy Medal is awarded by the Royal Society of London "for an outstandingly important recent discovery in any branch of chemistry". Named after Humphry Davy, the medal is awarded with a monetary gift, initially of £1000 (currently £2000). History The medal was first awarded in 1877 to Robert Wilhelm Bunsen and Gustav Robert Kirchhoff "for their researches & discoveries in spectrum analysis", and has since been awarded 140 times. The medal is awarded annually and, unlike other Royal Society medals (such as the Hughes), has been awarded without interruption since its inception. The medal has been awarded to multiple individuals in the same year: in 1882, for example, it was awarded to Dmitri Mendeleev and Julius Lothar Meyer "for their discovery of the periodic relations of the atomic weights"; in 1883 to Marcellin Berthelot and Julius Thomsen "for their researches in thermo-chemistry"; in 1893 to Jacobus Henricus van 't Hoff and Joseph Achille Le Bel "In recognition of thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Svante Arrhenius
Svante August Arrhenius ( , ; 19 February 1859 – 2 October 1927) was a Swedes, Swedish scientist. Originally a physicist, but often referred to as a chemist, Arrhenius was one of the founders of the science of physical chemistry. He received the Nobel Prize for Chemistry in 1903, becoming the first Sweden, Swedish Nobel laureate. In 1905, he became director of the Nobel Institute, where he remained until his death."Arrhenius, Svante August" in ''Chambers's Encyclopædia''. London: George Newnes Ltd, George Newnes, 1961, Vol. 1, p. 635. Arrhenius was the first to use principles of physical chemistry to estimate the extent to which increases in atmospheric carbon dioxide are responsible for the Earth's increasing surface temperature. His work played an important role in the emergence of modern climate science. In the 1960s, Charles David Keeling demonstrated that the quantity of human-caused carbon dioxide emissions into the air is enough to cause global warming. The Arrhenius ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freezing Point
The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at a standard pressure such as 1 atmosphere or 100 kPa. When considered as the temperature of the reverse change from liquid to solid, it is referred to as the freezing point or crystallization point. Because of the ability of substances to supercool, the freezing point can easily appear to be below its actual value. When the "characteristic freezing point" of a substance is determined, in fact, the actual methodology is almost always "the principle of observing the disappearance rather than the formation of ice, that is, the melting point." Examples For most substances, melting and freezing points are approximately equal. For example, the melting point ''and'' freezing point of mercury is . Ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Weight
A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and biochemistry, the distinction from ions is dropped and ''molecule'' is often used when referring to polyatomic ions. A molecule may be homonuclear, that is, it consists of atoms of one chemical element, e.g. two atoms in the oxygen molecule (O2); or it may be heteronuclear, a chemical compound composed of more than one element, e.g. water (two hydrogen atoms and one oxygen atom; H2O). In the kinetic theory of gases, the term ''molecule'' is often used for any gaseous particle regardless of its composition. This relaxes the requirement that a molecule contains two or more atoms, since the noble gases are individual atoms. Atoms and complexes connected by non-covalent interactions, such as hydrogen bonds or ionic bonds, are typically not consi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid Dissociation Constant
In chemistry, an acid dissociation constant (also known as acidity constant, or acid-ionization constant; denoted ) is a quantitative measure of the strength of an acid in solution. It is the equilibrium constant for a chemical reaction :HA A^- + H^+ known as dissociation in the context of acid–base reactions. The chemical species HA is an acid that dissociates into , the conjugate base of the acid and a hydrogen ion, . The system is said to be in equilibrium when the concentrations of its components will not change over time, because both forward and backward reactions are occurring at the same rate. The dissociation constant is defined by :K_\text = \mathrm, or :\mathrmK_\ce = - \log_ K_\text = \log_\frac where quantities in square brackets represent the concentrations of the species at equilibrium. Theoretical background The acid dissociation constant for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the p''K''a v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dicarboxylic Acid
In organic chemistry, a dicarboxylic acid is an organic compound containing two carboxyl groups (). The general molecular formula for dicarboxylic acids can be written as , where R can be aliphatic or aromatic. In general, dicarboxylic acids show similar chemical behavior and reactivity to monocarboxylic acids. Dicarboxylic acids are used in the preparation of copolymers such as polyamides and polyesters. The most widely used dicarboxylic acid in the industry is adipic acid, which is a precursor in the production of nylon. Other examples of dicarboxylic acids include aspartic acid and glutamic acid, two amino acids in the human body. The name can be abbreviated to diacid. Linear saturated dicarboxylic acids The general formula is .Boy Cornils, Peter Lappe "Dicarboxylic Acids, Aliphatic" in Ullmann's Encyclopedia of Industrial Chemistry 2014, Wiley-VCH, Weinheim. The PubChem links gives access to more information on the compounds, including other names, ids, toxicity and safety ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrolysis
In chemistry and manufacturing, electrolysis is a technique that uses direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. The voltage that is needed for electrolysis to occur is called the decomposition potential. The word "lysis" means to separate or break, so in terms, electrolysis would mean "breakdown via electricity". Etymology The word "electrolysis" was introduced by Michael Faraday in 1834, using the Greek words "amber", which since the 17th century was associated with electrical phenomena, and ' meaning "dissolution". Nevertheless, electrolysis, as a tool to study chemical reactions and obtain pure elements, precedes the coinage of the term and formal description by Faraday. History In the early nineteenth century, William Nicholson and Anthony Carlisle sought to further Volt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Chemistry
Physical chemistry is the study of macroscopic and microscopic phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mechanics, analytical dynamics and chemical equilibria. Physical chemistry, in contrast to chemical physics, is predominantly (but not always) a supra-molecular science, as the majority of the principles on which it was founded relate to the bulk rather than the molecular or atomic structure alone (for example, chemical equilibrium and colloids). Some of the relationships that physical chemistry strives to resolve include the effects of: # Intermolecular forces that act upon the physical properties of materials ( plasticity, tensile strength, surface tension in liquids). # Reaction kinetics on the rate of a reaction. # The identity of ions and the electrical conductivity of materials. # Surface science and electrochemistry of cell membrane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
