1.
Chemical compound
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A chemical compound is an entity consisting of two or more atoms, at least two from different elements, which associate via chemical bonds. Many chemical compounds have a numerical identifier assigned by the Chemical Abstracts Service. For example, water is composed of two atoms bonded to one oxygen atom, the chemical formula is H2O. A compound can be converted to a different chemical composition by interaction with a chemical compound via a chemical reaction. In this process, bonds between atoms are broken in both of the compounds, and then bonds are reformed so that new associations are made between atoms. Schematically, this reaction could be described as AB + CD → AC + BD, where A, B, C, and D are each unique atoms, and AB, CD, AC, and BD are each unique compounds. A chemical element bonded to a chemical element is not a chemical compound since only one element. Examples are the diatomic hydrogen and the polyatomic molecule sulfur. Chemical compounds have a unique and defined chemical structure held together in a spatial arrangement by chemical bonds. Pure chemical elements are not considered chemical compounds, failing the two or more atom requirement, though they often consist of molecules composed of multiple atoms. There is varying and sometimes inconsistent nomenclature differentiating substances, which include truly non-stoichiometric examples, from chemical compounds, other compounds regarded as chemically identical may have varying amounts of heavy or light isotopes of the constituent elements, which changes the ratio of elements by mass slightly. Characteristic properties of compounds include that elements in a compound are present in a definite proportion, for example, the molecule of the compound water is composed of hydrogen and oxygen in a ratio of 2,1. In addition, compounds have a set of properties. The physical and chemical properties of compounds differ from those of their constituent elements, however, mixtures can be created by mechanical means alone, but a compound can be created only by a chemical reaction. Some mixtures are so combined that they have some properties similar to compounds. Other examples of compound-like mixtures include intermetallic compounds and solutions of metals in a liquid form of ammonia. Compounds may be described using formulas in various formats, for compounds that exist as molecules, the formula for the molecular unit is shown. For polymeric materials, such as minerals and many metal oxides, the elements in a chemical formula are normally listed in a specific order, called the Hill system
2.
International Union of Pure and Applied Chemistry
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The International Union of Pure and Applied Chemistry /ˈaɪjuːpæk/ or /ˈjuːpæk/ is an international federation of National Adhering Organizations that represents chemists in individual countries. It is a member of the International Council for Science, IUPAC is registered in Zürich, Switzerland, and the administrative office, known as the IUPAC Secretariat, is in Research Triangle Park, North Carolina, United States. This administrative office is headed by IUPACs executive director, currently Lynn Soby, IUPAC was established in 1919 as the successor of the International Congress of Applied Chemistry for the advancement of chemistry. Its members, the National Adhering Organizations, can be national chemistry societies, national academies of sciences, there are fifty-four National Adhering Organizations and three Associate National Adhering Organizations. IUPACs Inter-divisional Committee on Nomenclature and Symbols is the world authority in developing standards for the naming of the chemical elements. Since its creation, IUPAC has been run by different committees with different responsibilities. These committees run different projects which include standardizing nomenclature, finding ways to bring chemistry to the world, IUPAC is best known for its works standardizing nomenclature in chemistry and other fields of science, but IUPAC has publications in many fields including chemistry, biology and physics. IUPAC is also known for standardizing the atomic weights of the elements through one of its oldest standing committees, the need for an international standard for chemistry was first addressed in 1860 by a committee headed by German scientist Friedrich August Kekulé von Stradonitz. This committee was the first international conference to create an international naming system for organic compounds, the ideas that were formulated in that conference evolved into the official IUPAC nomenclature of organic chemistry. IUPAC stands as a legacy of this meeting, making it one of the most important historical international collaborations of chemistry societies, since this time, IUPAC has been the official organization held with the responsibility of updating and maintaining official organic nomenclature. IUPAC as such was established in 1919, one notable country excluded from this early IUPAC is Germany. Germanys exclusion was a result of prejudice towards Germans by the Allied powers after World War I, Germany was finally admitted into IUPAC during 1929. However, Nazi Germany was removed from IUPAC during World War II, during World War II, IUPAC was affiliated with the Allied powers, but had little involvement during the war effort itself. After the war, East and West Germany were eventually readmitted to IUPAC, since World War II, IUPAC has been focused on standardizing nomenclature and methods in science without interruption. In 2016, IUPAC denounced the use of chlorine as a chemical weapon, the letter stated, Our organizations deplore the use of chlorine in this manner. According to the CWC, the use, stockpiling, distribution, IUPAC is governed by several committees that all have different responsibilities. Each committee is made up of members of different National Adhering Organizations from different countries, the steering committee hierarchy for IUPAC is as follows, All committees have an allotted budget to which they must adhere. Any committee may start a project, if a projects spending becomes too much for a committee to continue funding, it must take the issue to the Project Committee
3.
Organic compound
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An organic compound is virtually any chemical compound that contains carbon, although a consensus definition remains elusive and likely arbitrary. Organic compounds are rare terrestrially, but of importance because all known life is based on organic compounds. The most basic petrochemicals are considered the building blocks of organic chemistry, for historical reasons discussed below, a few types of carbon-containing compounds, such as carbides, carbonates, simple oxides of carbon, and cyanides are considered inorganic. The distinction between organic and inorganic compounds, while useful in organizing the vast subject of chemistry. Organic chemistry is the science concerned with all aspects of organic compounds, Organic synthesis is the methodology of their preparation. The word organic is historical, dating to the 1st century, for many centuries, Western alchemists believed in vitalism. This is the theory that certain compounds could be synthesized only from their classical elements—earth, water, air, vitalism taught that these organic compounds were fundamentally different from the inorganic compounds that could be obtained from the elements by chemical manipulation. Vitalism survived for a while even after the rise of modern atomic theory and it first came under question in 1824, when Friedrich Wöhler synthesized oxalic acid, a compound known to occur only in living organisms, from cyanogen. A more decisive experiment was Wöhlers 1828 synthesis of urea from the inorganic salts potassium cyanate, urea had long been considered an organic compound, as it was known to occur only in the urine of living organisms. Wöhlers experiments were followed by others, in which increasingly complex organic substances were produced from inorganic ones without the involvement of any living organism. Even though vitalism has been discredited, scientific nomenclature retains the distinction between organic and inorganic compounds, still, even the broadest definition requires excluding alloys that contain carbon, including steel. The C-H definition excludes compounds that are considered organic, neither urea nor oxalic acid is organic by this definition, yet they were two key compounds in the vitalism debate. The IUPAC Blue Book on organic nomenclature specifically mentions urea and oxalic acid, other compounds lacking C-H bonds but traditionally considered organic include benzenehexol, mesoxalic acid, and carbon tetrachloride. Mellitic acid, which contains no C-H bonds, is considered an organic substance in Martian soil. The C-H bond-only rule also leads to somewhat arbitrary divisions in sets of carbon-fluorine compounds, for example, CF4 would be considered by this rule to be inorganic, whereas CF3H would be organic. Organic compounds may be classified in a variety of ways, one major distinction is between natural and synthetic compounds. Another distinction, based on the size of organic compounds, distinguishes between small molecules and polymers, natural compounds refer to those that are produced by plants or animals. Many of these are extracted from natural sources because they would be more expensive to produce artificially
4.
IUPAC nomenclature of inorganic chemistry
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It is published in Nomenclature of Inorganic Chemistry. Ideally, every inorganic compound should have a name from which a formula can be determined. There is also an IUPAC nomenclature of organic chemistry, the names caffeine and 3, 7-dihydro-1,3, 7-trimethyl-1H-purine-2, 6-dione both signify the same chemical. The systematic name encodes the structure and composition of the molecule in some detail. These advantages make the systematic name far superior to the name when absolute clarity. However, for the sake of brevity, even professional chemists will use the name almost all of the time. Similarly, H2O is most often called water in English. Single atom anions are named with a suffix, for example. Compounds with an ion, The name of the compound is simply the cations name. For example, NaCl is sodium chloride, and CaF2 is calcium fluoride, cations which have taken on more than one positive charge are labeled with Roman numerals in parentheses. For example, Cu+ is copper, Cu2+ is copper, an older, deprecated notation is to append -ous or -ic to the root of the Latin name to name ions with a lesser or greater charge. Under this naming convention, Cu+ is cuprous and Cu2+ is cupric, for naming metal complexes see the page on complex. Oxyanions are named with -ite or -ate, for a lesser or greater quantity of oxygen, for example, NO−2 is nitrite, while NO−3 is nitrate. If four oxyanions are possible, the prefixes hypo- and per- are used, hypochlorite is ClO−, the prefix bi- is a deprecated way of indicating the presence of a single hydrogen ion, as in sodium bicarbonate. The modern method specifically names the hydrogen atom, thus, NaHCO3 would be pronounced sodium hydrogen carbonate. Positively charged ions are called cations and negatively charged ions are called anions, the cation is always named first. Ions can be metals or polyatomic ions, therefore, the name of the metal or positive polyatomic ion is followed by the name of the non-metal or negative polyatomic ion. The positive ion retains its element name whereas for a single non-metal anion the ending is changed to -ide, example, sodium chloride, potassium oxide, or calcium carbonate
5.
Symbol
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A symbol is a mark, sign, or word that indicates, signifies, or is understood as representing an idea, object, or relationship. Symbols allow people to go beyond what is known or seen by creating linkages between otherwise very different concepts and experiences, all communication is achieved through the use of symbols. Symbols take the form of words, sounds, gestures, ideas or visual images and are used to other ideas. For example, a red octagon may be a symbol for STOP, on a map, a blue line might represent a river. Alphabetic letters may be symbols for sounds, personal names are symbols representing individuals. A red rose may symbolize love and compassion, the variable x, in a mathematical equation, may symbolize the position of a particle in space. In cartography, a collection of symbols forms a legend for a map The word derives from the Greek symbolon meaning token or watchword. It is an amalgam of syn- together + bole a throwing, a casting, the sense evolution in Greek is from throwing things together to contrasting to comparing to token used in comparisons to determine if something is genuine. The meaning something which stands for something else was first recorded in 1590, later, expanding on what he means by this definition Campbell says, a symbol, like everything else, shows a double aspect. We must distinguish, therefore between the sense and the meaning of the symbol. The term meaning can only to the first two but these, today, are in the charge of science – which is the province as we have said, not of symbols. The ineffable, the unknowable, can be only sensed. Heinrich Zimmer gives an overview of the nature, and perennial relevance. Concepts and words are symbols, just as visions, rituals, through all of these a transcendent reality is mirrored. They are so many metaphors reflecting and implying something which, though thus variously expressed, is ineffable, though thus rendered multiform, Symbols hold the mind to truth but are not themselves the truth, hence it is delusory to borrow them. Each civilisation, every age, must bring forth its own, in the book Signs and Symbols, it is stated that A symbol. Is a visual image or sign representing an idea -- a deeper indicator of a universal truth, Symbols are a means of complex communication that often can have multiple levels of meaning. This separates symbols from signs, as signs have only one meaning, human cultures use symbols to express specific ideologies and social structures and to represent aspects of their specific culture
6.
IUPAC books
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The Compendium of Chemical Terminology is a book published by the International Union of Pure and Applied Chemistry containing internationally accepted definitions for terms in chemistry. Work on the first edition was initiated by Victor Gold, hence its informal name, the first edition was published in 1987 and the second edition, edited by A. D. McNaught and A. Wilkinson, was published in 1997. A slightly expanded version of the Gold Book is also freely searchable online, translations have also been published in French, Spanish and Polish
7.
Biochemistry
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Biochemistry, sometimes called biological chemistry, is the study of chemical processes within and relating to living organisms. By controlling information flow through biochemical signaling and the flow of energy through metabolism. Biochemistry is closely related to biology, the study of the molecular mechanisms by which genetic information encoded in DNA is able to result in the processes of life. Depending on the definition of the terms used, molecular biology can be thought of as a branch of biochemistry, or biochemistry as a tool with which to investigate. The chemistry of the cell depends on the reactions of smaller molecules. These can be inorganic, for water and metal ions, or organic, for example the amino acids. The mechanisms by which cells harness energy from their environment via chemical reactions are known as metabolism, the findings of biochemistry are applied primarily in medicine, nutrition, and agriculture. In medicine, biochemists investigate the causes and cures of diseases, in nutrition, they study how to maintain health and study the effects of nutritional deficiencies. In agriculture, biochemists investigate soil and fertilizers, and try to discover ways to improve crop cultivation, crop storage and pest control. However, biochemistry as a scientific discipline has its beginning sometime in the 19th century, or a little earlier. Gowland Hopkins on enzymes and the nature of biochemistry. The term biochemistry itself is derived from a combination of biology, the German chemist Carl Neuberg however is often cited to have coined the word in 1903, while some credited it to Franz Hofmeister. Then, in 1828, Friedrich Wöhler published a paper on the synthesis of urea and these techniques allowed for the discovery and detailed analysis of many molecules and metabolic pathways of the cell, such as glycolysis and the Krebs cycle. Another significant historic event in biochemistry is the discovery of the gene and this part of biochemistry is often called molecular biology. In the 1950s, James D. Watson, Francis Crick, Rosalind Franklin, in 1958, George Beadle and Edward Tatum received the Nobel Prize for work in fungi showing that one gene produces one enzyme. In 1988, Colin Pitchfork was the first person convicted of murder with DNA evidence, mello received the 2006 Nobel Prize for discovering the role of RNA interference, in the silencing of gene expression. Around two dozen of the 92 naturally occurring elements are essential to various kinds of biological life. Most rare elements on Earth are not needed by life, while a few common ones are not used, most organisms share element needs, but there are a few differences between plants and animals
8.
Analytical chemistry
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Analytical chemistry studies and uses instruments and methods used to separate, identify, and quantify matter. In practice separation, identification or quantification may constitute the entire analysis or be combined with another method, qualitative analysis identifies analytes, while quantitative analysis determines the numerical amount or concentration. Analytical chemistry consists of classical, wet chemical methods and modern, classical qualitative methods use separations such as precipitation, extraction, and distillation. Identification may be based on differences in color, odor, melting point, boiling point, classical quantitative analysis uses mass or volume changes to quantify amount. Instrumental methods may be used to separate samples using chromatography, electrophoresis or field flow fractionation, then qualitative and quantitative analysis can be performed, often with the same instrument and may use light interaction, heat interaction, electric fields or magnetic fields. Often the same instrument can separate, identify and quantify an analyte, Analytical chemistry is also focused on improvements in experimental design, chemometrics, and the creation of new measurement tools. Analytical chemistry has applications to forensics, medicine, science. Analytical chemistry has been important since the days of chemistry, providing methods for determining which elements. The first instrumental analysis was flame emissive spectrometry developed by Robert Bunsen, most of the major developments in analytical chemistry take place after 1900. During this period instrumental analysis becomes progressively dominant in the field, in particular many of the basic spectroscopic and spectrometric techniques were discovered in the early 20th century and refined in the late 20th century. The separation sciences follow a similar line of development and also become increasingly transformed into high performance instruments. In the 1970s many of these began to be used together as hybrid techniques to achieve a complete characterization of samples. Lasers have been used in chemistry as probes and even to initiate. Modern analytical chemistry is dominated by instrumental analysis, many analytical chemists focus on a single type of instrument. Academics tend to focus on new applications and discoveries or on new methods of analysis. The discovery of a present in blood that increases the risk of cancer would be a discovery that an analytical chemist might be involved in. An effort to develop a new method might involve the use of a laser to increase the specificity and sensitivity of a spectrometric method. Many methods, once developed, are kept purposely static so that data can be compared over long periods of time and this is particularly true in industrial quality assurance, forensic and environmental applications
9.
Scientific journal
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In academic publishing, a scientific journal is a periodical publication intended to further the progress of science, usually by reporting new research. There are thousands of journals in publication, and many more have been published at various points in the past. Most journals are highly specialized, although some of the oldest journals such as Nature publish articles, Scientific journals contain articles that have been peer reviewed, in an attempt to ensure that articles meet the journals standards of quality, and scientific validity. If the journals editor considers the paper appropriate, at least two researchers preferably from the same field check the paper for soundness of its scientific argument, although scientific journals are superficially similar to professional magazines, they are actually quite different. Issues of a scientific journal are rarely read casually, as one would read a magazine, the publication of the results of research is an essential part of the scientific method. If they are describing experiments or calculations, they must supply enough details that an independent researcher could repeat the experiment or calculation to verify the results, each such journal article becomes part of the permanent scientific record. Over a thousand, mostly ephemeral, were founded in the 18th century, articles in scientific journals can be used in research and higher education. Scientific articles allow researchers to keep up to date with the developments of their field, an essential part of a scientific article is citation of earlier work. The impact of articles and journals is often assessed by counting citations, some classes are partially devoted to the explication of classic articles, and seminar classes can consist of the presentation by each student of a classic or current paper. Schoolbooks and textbooks have been written only on established topics, while the latest research. In a scientific research group or academic department it is usual for the content of current scientific journals to be discussed in journal clubs, the standards that a journal uses to determine publication can vary widely. Some journals, such as Nature, Science, PNAS, and it is also common for journals to have a regional focus, specializing in publishing papers from a particular country or other geographic region, like African Invertebrates. Articles tend to be technical, representing the latest theoretical research. They are often incomprehensible to anyone except for researchers in the field, in some subjects this is inevitable given the nature of the content. Usually, rigorous rules of writing are enforced by the editors, however. Articles are usually either original articles reporting new results or reviews of current literature. There are also publications that bridge the gap between articles and books by publishing thematic volumes of chapters from different authors. Research notes are short descriptions of current research findings that are considered less urgent or important than Letters, supplemental articles contain a large volume of tabular data that is the result of current research and may be dozens or hundreds of pages with mostly numerical data
10.
American Chemical Society
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The American Chemical Society is a scientific society based in the United States that supports scientific inquiry in the field of chemistry. Founded in 1876 at New York University, the ACS currently has more than 158,000 members at all levels and in all fields of chemistry, chemical engineering. It is the worlds largest scientific society by membership, the ACS is a 501 non-profit organization and holds a congressional charter under Title 36 of the United States Code. Its headquarters are located in Washington, D. C. and it has a concentration of staff in Columbus. The ACS is a source of scientific information through its peer-reviewed scientific journals, national conferences. Its publications division produces 51 scholarly journals including the prestigious Journal of the American Chemical Society, the ACS holds national meetings twice a year covering the complete field of chemistry and also holds smaller conferences concentrating on specific chemical fields or geographic regions. The primary source of income of the ACS is the Chemical Abstracts Service, the organization also publishes textbooks, administers several national chemistry awards, provides grants for scientific research, and supports various educational and outreach activities. In 1874, a group of American chemists gathered at the Joseph Priestley House to mark the 100th anniversary of Priestleys discovery of oxygen. Two years later, on 6 April 1876, during a meeting of chemists at the University of the City of New York the American Chemical Society was founded, the society received its charter of incorporation from the State of New York in 1877. Charles F. Draper was a photochemist and pioneering photographer who had produced one of the first photographic portraits in 1840, chandler would later serve as president in 1881 and 1889. The Journal of the American Chemical Society was founded in 1879 to publish original chemical research and it was the first journal published by ACS and is still the societys flagship peer-reviewed publication. Chemical & Engineering News is a trade magazine that has been published by ACS since 1923. The society adopted a new constitution aimed at nationalizing the organization in 1890, in 1905, the American Chemical Society moved from New York City to Washington, D. C. ACS was reincorporated under a charter in 1937. It was granted by the U. S. Congress and signed by president Franklin D. Roosevelt, ACSs headquarters moved to its current location in downtown Washington in 1941. Divisional activities include organizing technical sessions at ACS meetings, publishing books and resources, administering awards and lectureships, as of 2016, there are 32 technical divisions of ACS. This is the largest division of the Society and it marked its 100th Anniversary in 2008. The first Chair of the Division was Edward Curtis Franklin, the Organic Division played a part in establishing Organic Syntheses, Inc. and Organic Reactions, Inc. and it maintains close ties to both organizations
11.
Trivial name
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In chemistry, a trivial name is a nonsystematic name for a chemical substance. That is, the name is not recognized according to the rules of any system of chemical nomenclature such as IUPAC inorganic or IUPAC organic nomenclature. A trivial name is not a name and is usually a common name. Generally, trivial names are not useful in describing the properties of the thing being named. Properties such as the structure of a chemical compound are not indicated. And, in cases, trivial names can be ambiguous or will carry different meanings in different industries or in different geographic regions. On the other hand, systematic names can be so convoluted, as a result, a limited number of trivial chemical names are retained names, an accepted part of the nomenclature. Trivial names often arise in the language, they may come from historic usages in, for example. Many trivial names pre-date the institution of formal naming conventions, all elements that have been isolated have trivial names. In scientific documents, international treaties, patents and legal definitions and this need is satisfied by systematic names. One such system, established by the International Union of Pure, other systems have been developed by the American Chemical Society, the International Organization for Standardization, and the World Health Organization. However, chemists still use names that are not systematic because they are traditional or because they are more convenient than the systematic names. The word trivial, often used in a sense, was intended to mean commonplace. In addition to names, chemists have constructed semi-trivial names by appending a standard symbol to a trivial stem. Some trivial and semi-trivial names are so used that they have been officially adopted by IUPAC. Traditional names of elements are trivial, some originating in alchemy, IUPAC has accepted these names, but has also defined systematic names of elements that have not yet been prepared. It has adopted a procedure by which the scientists who are credited with preparing an element can propose a new name, once the IUPAC has accepted such a name, it replaces the systematic name. Nine elements were known by the Middle Ages – gold, silver, tin, mercury, copper, lead, iron, sulfur, and carbon
12.
Chemical formula
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These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulas can fully specify the structure of only the simplest of molecules and chemical substances, the simplest types of chemical formulas are called empirical formulas, which use letters and numbers indicating the numerical proportions of atoms of each type. Molecular formulas indicate the numbers of each type of atom in a molecule. For example, the formula for glucose is CH2O, while its molecular formula is C6H12O6. This is possible if the relevant bonding is easy to show in one dimension, an example is the condensed molecular/chemical formula for ethanol, which is CH3-CH2-OH or CH3CH2OH. For reasons of structural complexity, there is no condensed chemical formula that specifies glucose, chemical formulas may be used in chemical equations to describe chemical reactions and other chemical transformations, such as the dissolving of ionic compounds into solution. A chemical formula identifies each constituent element by its chemical symbol, in empirical formulas, these proportions begin with a key element and then assign numbers of atoms of the other elements in the compound, as ratios to the key element. For molecular compounds, these numbers can all be expressed as whole numbers. For example, the formula of ethanol may be written C2H6O because the molecules of ethanol all contain two carbon atoms, six hydrogen atoms, and one oxygen atom. Some types of compounds, however, cannot be written with entirely whole-number empirical formulas. An example is boron carbide, whose formula of CBn is a variable non-whole number ratio with n ranging from over 4 to more than 6.5. When the chemical compound of the consists of simple molecules. These types of formulas are known as molecular formulas and condensed formulas. A molecular formula enumerates the number of atoms to reflect those in the molecule, so that the formula for glucose is C6H12O6 rather than the glucose empirical formula. However, except for very simple substances, molecular chemical formulas lack needed structural information, for simple molecules, a condensed formula is a type of chemical formula that may fully imply a correct structural formula. For example, ethanol may be represented by the chemical formula CH3CH2OH
13.
Chemical Abstracts Service
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Chemical Abstracts Service is a division of the American Chemical Society. It is a source of chemical information, CAS is located in Columbus, Ohio, United States. Chemical Abstracts is an index that provides summaries and indexes of disclosures in recently published scientific documents. Chemical Abstracts ceased print publication on January 1,2010, the two principal databases that support the different products are CAplus and Registry. Registry contains information on more than 71 million organic and inorganic substances, the sequence information comes from CAS and GenBank, produced by the National Institutes of Health. CAS databases are available via two principal database systems, STN, and SciFinder, STN International is operated jointly by CAS and FIZ Karlsruhe, and is intended primarily for information professionals, using a command language interface. In addition to CAS databases, STN also provides access to other databases. SciFinder is a database of chemical and bibliographic information, originally a client application, a web version was released in 2008. It has an interface, and can be searched for chemical structures. The client version is for chemists in commercial organizations, versions for both the Windows and Macintosh exist. SciFinder Scholar is for universities and other institutions and lacks some supplementary features for multi-database searching. CASSI stands for Chemical Abstracts Service Source Index, since 2009 this formerly print and CD-ROM compilation is available as a free online resource to look up and confirm publication information. The online CASSI Search Tool provides titles and abbreviations, CODEN, ISSN, publisher, also included is its language of text and language of summaries. The range is from 1907 to the present, including serial and non-serial scientific and technical publications. Beyond CASSI lists abbreviated journal titles from early literature and other historical reference sources. Chemical Abstracts began as an effort and developed from there. The use of volunteer abstractors was phased out in 1994, Chemical Abstracts has been associated with the American Chemical Society in one way or another since 1907. For many years, beginning in 1909, the offices of Chemical Abstracts were housed in places on the campus of Ohio State University in Columbus
14.
International Chemical Identifier
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Initially developed by IUPAC and NIST from 2000 to 2005, the format and algorithms are non-proprietary. The continuing development of the standard has supported since 2010 by the not-for-profit InChI Trust. The current version is 1.04 and was released in September 2011, prior to 1.04, the software was freely available under the open source LGPL license, but it now uses a custom license called IUPAC-InChI Trust License. Not all layers have to be provided, for instance, the layer can be omitted if that type of information is not relevant to the particular application. InChIs can thus be seen as akin to a general and extremely formalized version of IUPAC names and they can express more information than the simpler SMILES notation and differ in that every structure has a unique InChI string, which is important in database applications. Information about the 3-dimensional coordinates of atoms is not represented in InChI, the InChI algorithm converts input structural information into a unique InChI identifier in a three-step process, normalization, canonicalization, and serialization. The InChIKey, sometimes referred to as a hashed InChI, is a fixed length condensed digital representation of the InChI that is not human-understandable. The InChIKey specification was released in September 2007 in order to facilitate web searches for chemical compounds and it should be noted that, unlike the InChI, the InChIKey is not unique, though collisions can be calculated to be very rare, they happen. In January 2009 the final 1.02 version of the InChI software was released and this provided a means to generate so called standard InChI, which does not allow for user selectable options in dealing with the stereochemistry and tautomeric layers of the InChI string. The standard InChIKey is then the hashed version of the standard InChI string, the standard InChI will simplify comparison of InChI strings and keys generated by different groups, and subsequently accessed via diverse sources such as databases and web resources. Every InChI starts with the string InChI= followed by the version number and this is followed by the letter S for standard InChIs. The remaining information is structured as a sequence of layers and sub-layers, the layers and sub-layers are separated by the delimiter / and start with a characteristic prefix letter. The six layers with important sublayers are, Main layer Chemical formula and this is the only sublayer that must occur in every InChI. The atoms in the formula are numbered in sequence, this sublayer describes which atoms are connected by bonds to which other ones. Describes how many hydrogen atoms are connected to each of the other atoms, the condensed,27 character standard InChIKey is a hashed version of the full standard InChI, designed to allow for easy web searches of chemical compounds. Most chemical structures on the Web up to 2007 have been represented as GIF files, the full InChI turned out to be too lengthy for easy searching, and therefore the InChIKey was developed. With all databases currently having below 50 million structures, such duplication appears unlikely at present, a recent study more extensively studies the collision rate finding that the experimental collision rate is in agreement with the theoretical expectations. Example, Morphine has the structure shown on the right, as the InChI cannot be reconstructed from the InChIKey, an InChIKey always needs to be linked to the original InChI to get back to the original structure
15.
Allotropes of sulfur
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The allotropes of sulfur refers to the many allotropes of the element sulfur. In terms of number of allotropes, sulfur is second only to carbon. In addition to the allotropes, each allotrope often exists in polymorphs, furthermore, because elemental sulfur has been an item of commerce for centuries, its various forms are given traditional names. Early workers identified some forms that have proved to be single or mixtures of allotropes. Some forms have been named for their appearance, e. g. mother of pearl sulfur, or alternatively named for a chemist who was pre-eminent in identifying them, e. g. Muthmanns sulfur I or Engels sulfur. The most commonly encountered form of sulfur is the polymorph of S8. Two other polymorphs are known, also nearly identical molecular structures. In addition to S8, sulfur rings of 6,7, at least five allotropes are uniquely formed at high pressures, two of which are metallic. The number of sulfur allotropes reflects the relatively strong S−S bond of 265 kJ/mol, furthermore, unlike most elements, the allotropes of sulfur can be manipulated in solutions of organic solvents and is amenable to analysis by HPLC. The pressure-temperature phase diagram for sulfur is complex, the region labeled I, is α-sulfur. See the legend for further identifications and information, and see the section on high pressure forms for information on these phases. In a high-pressure study at ambient temperatures, four new forms, termed II, III, IV, V have been characterized. Solid forms II and III are polymeric, while IV and V are metallic, laser irradiation of solid samples produces three sulfur forms below 200–300 kbar. Two methods exist for the preparation of the cyclo-sulfur allotropes and this was first prepared by M. R. Engel in 1891 by reacting HCl with thiosulfate, HS2O3−. Cyclo-S6 is orange-red and forms a rhombohedral crystal and it is called ρ-sulfur, ε-sulfur, Engels sulfur and Atens sulfur. All of the atoms are equivalent. It is a yellow solid. Four forms of cyclo-heptasulfur are known, the cyclo-S7 ring has an unusual range of bond lengths of 199. 3–218.1 pm
16.
Sirolimus
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Sirolimus, also known as rapamycin, is a macrolide compound that is used to coat coronary stents, prevent organ transplant rejection and to treat a rare lung disease called lymphangioleiomyomatosis. It has immunosuppressant functions in humans and is useful in preventing the rejection of kidney transplants. It inhibits activation of T cells and B cells by reducing the production of interleukin-2, the compound was originally named rapamycin after the native name of the island, Rapa Nui. Sirolimus was initially developed as an antifungal agent, however, this use was abandoned when it was discovered to have potent immunosuppressive and antiproliferative properties due to its ability to inhibit mTOR. It was approved by the US Food and Drug Administration in September 1999 and is marketed under the trade name Rapamune by Pfizer, sirolimus is indicated for the prevention of organ transplant rejection and for the treatment of lymphangioleiomyomatosis. The chief advantage sirolimus has over calcineurin inhibitors is its low toxicity toward kidneys, transplant patients maintained on calcineurin inhibitors long-term tend to develop impaired kidney function or even chronic renal failure, this can be avoided by using sirolimus instead. It is particularly advantageous in patients with kidney transplants for hemolytic-uremic syndrome, however, on 7 October 2008, the FDA approved safety labeling revisions for sirolimus to warn of the risk for decreased renal function associated with its use. Sirolimus can also be used alone, or in conjunction with an inhibitor, and/or mycophenolate mofetil. Its optimal role in immunosuppression has not yet determined. On May 28,2015, the FDA approved sirolimus to treat lymphangioleiomyomatosis and this made sirolimus the first drug approved to treat this disease. LAM involves lung tissue infiltration with smooth muscle-like cells with mutations of the tuberous sclerosis complex gene, loss of TSC2 gene function activates the mTOR signaling pathway, resulting in the release of lymphangiogenic growth factors. The safety and efficacy of treatment of LAM were investigated in clinical trials that compared sirolimus treatment with a placebo group in 89 patients for 12 months. The patients were observed for 12 months after the treatment had ended, serious side effects including hypersensitivity and swelling have been observed in renal transplant patients. While sirolimus was considered for treatment of LAM, it received orphan product designation status because LAM is a rare condition, the safety of LAM treatment by sirolimus in patients younger than 18 years old has not been tested. The antiproliferative effect of sirolimus has also used in conjunction with coronary stents to prevent restenosis in coronary arteries following balloon angioplasty. The sirolimus is formulated in a coating that affords controlled release through the healing period following coronary intervention. Several large clinical studies have demonstrated lower restenosis rates in patients treated with sirolimus-eluting stents when compared to bare-metal stents, a sirolimus-eluting coronary stent was marketed by Cordis, a division of Johnson & Johnson, under the tradename Cypher. However, this kind of stent may also increase the risk of vascular thrombosis, sirolimus is contraindicated in individuals with a known hypersensitivity to the drug
17.
IUPAC
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The International Union of Pure and Applied Chemistry /ˈaɪjuːpæk/ or /ˈjuːpæk/ is an international federation of National Adhering Organizations that represents chemists in individual countries. It is a member of the International Council for Science, IUPAC is registered in Zürich, Switzerland, and the administrative office, known as the IUPAC Secretariat, is in Research Triangle Park, North Carolina, United States. This administrative office is headed by IUPACs executive director, currently Lynn Soby, IUPAC was established in 1919 as the successor of the International Congress of Applied Chemistry for the advancement of chemistry. Its members, the National Adhering Organizations, can be national chemistry societies, national academies of sciences, there are fifty-four National Adhering Organizations and three Associate National Adhering Organizations. IUPACs Inter-divisional Committee on Nomenclature and Symbols is the world authority in developing standards for the naming of the chemical elements. Since its creation, IUPAC has been run by different committees with different responsibilities. These committees run different projects which include standardizing nomenclature, finding ways to bring chemistry to the world, IUPAC is best known for its works standardizing nomenclature in chemistry and other fields of science, but IUPAC has publications in many fields including chemistry, biology and physics. IUPAC is also known for standardizing the atomic weights of the elements through one of its oldest standing committees, the need for an international standard for chemistry was first addressed in 1860 by a committee headed by German scientist Friedrich August Kekulé von Stradonitz. This committee was the first international conference to create an international naming system for organic compounds, the ideas that were formulated in that conference evolved into the official IUPAC nomenclature of organic chemistry. IUPAC stands as a legacy of this meeting, making it one of the most important historical international collaborations of chemistry societies, since this time, IUPAC has been the official organization held with the responsibility of updating and maintaining official organic nomenclature. IUPAC as such was established in 1919, one notable country excluded from this early IUPAC is Germany. Germanys exclusion was a result of prejudice towards Germans by the Allied powers after World War I, Germany was finally admitted into IUPAC during 1929. However, Nazi Germany was removed from IUPAC during World War II, during World War II, IUPAC was affiliated with the Allied powers, but had little involvement during the war effort itself. After the war, East and West Germany were eventually readmitted to IUPAC, since World War II, IUPAC has been focused on standardizing nomenclature and methods in science without interruption. In 2016, IUPAC denounced the use of chlorine as a chemical weapon, the letter stated, Our organizations deplore the use of chlorine in this manner. According to the CWC, the use, stockpiling, distribution, IUPAC is governed by several committees that all have different responsibilities. Each committee is made up of members of different National Adhering Organizations from different countries, the steering committee hierarchy for IUPAC is as follows, All committees have an allotted budget to which they must adhere. Any committee may start a project, if a projects spending becomes too much for a committee to continue funding, it must take the issue to the Project Committee
18.
Resveratrol
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Resveratrol is a stilbenoid, a type of natural phenol, and a phytoalexin produced by several plants in response to injury or when the plant is under attack by pathogens such as bacteria or fungi. Sources of resveratrol in food include the skin of grapes, blueberries, raspberries, mulberries, although it is used as a dietary supplement, there is no clear evidence that consuming resveratrol affects life expectancy or human health. There is no evidence of benefit from resveratrol in those who already have heart disease, a 2014 Chinese meta-analysis found weak evidence that high-dose resveratrol supplementation could reduce systolic blood pressure. As of 2016, there is no evidence of an effect of resveratrol on cancer in humans, there is no conclusive human evidence for an effect of resveratrol on metabolism. There is no evidence for an effect of resveratrol on lifespan in humans as of 2011, in 2010, GlaxoSmithKline suspended a small clinical trial of SRT501, a proprietary form of resveratrol, due to safety concerns, and terminated the study later that year. Although in vitro studies indicate resveratrol activates sirtuin 1 and PGC-1α, in cells treated with resveratrol, an increase is observed in the action of MnSOD and in GPER activity. One way of administering resveratrol in humans may be buccal delivery and this level of unchanged resveratrol in blood can only be achieved with 250 mg of resveratrol taken in a pill form. However, the viability of a delivery method is called into question due to the low aqueous solubility of the molecule. For a drug to be absorbed transmucosally it must be in free-form or dissolved, resveratrol fits the criteria for oral transmucosal dosing, except for this caveat. The low aqueous solubility greatly limits the amount that can be absorbed through the buccal mucosa, while 70% of orally administered resveratrol is absorbed, its oral bioavailability is approximately 0. 5% due to extensive hepatic glucuronidation and sulfation. Resveratrol given in a proprietary formulation SRT-501, developed by Sirtris Pharmaceuticals and these levels did approach the concentration necessary to exert the effects shown in animal models and in vitro experiments. In rats, less than 5% of the dose was observed as free resveratrol in blood plasma. There is a hypothesis that resveratrol from wine could have higher bioavailability than resveratrol from a pill, in a human study involving oral administration of 500 mg over 13 weeks, resveratrol was detected in cerebrospinal fluid, indicating that it had crossed the blood-brain barrier. Resveratrol gets extensively metabolized in the body, with the liver, resveratrol is a stilbenoid, a derivative of stilbene. It exists as two isomers, cis- and trans-, with the trans-isomer shown in the top image. The trans- and cis-resveratrol can be free or bound to glucose. Trans-resveratrol in the form was found to be stable under accelerated stability conditions of 75% humidity and 40 °C in the presence of air. The trans isomer is also stabilized by the presence of transport proteins, resveratrol content also was stable in the skins of grapes and pomace taken after fermentation and stored for a long period
19.
Omega-3 fatty acid
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Omega-3 fatty acids—also called ω-3 fatty acids or n-3 fatty acids—are polyunsaturated fatty acids with a double bond at the third carbon atom from the end of the carbon chain. One way in which a fatty acid is named is determined by the location of the first double bond, counted from the end, that is. However, the chemical nomenclature system starts from the carbonyl end. The three types of fatty acids involved in human physiology are α-linolenic acid, eicosapentaenoic acid. Marine algae and phytoplankton are primary sources of fatty acids. Dietary supplementation with omega-3 fatty acids does not appear to affect the risk of death, furthermore, fish oil supplement studies have failed to support claims of preventing heart attacks or strokes. Omega-3 fatty acids are important for normal metabolism, the ability to make the longer-chain omega-3 fatty acids from ALA may be impaired in aging. In foods exposed to air, unsaturated fatty acids are vulnerable to oxidation, supplementation does not appear to be associated with a lower risk of all-cause mortality. The evidence linking the consumption of fish to the risk of cancer is poor, supplementation with omega-3 fatty acids does not appear to affect this either. A2006 review concluded there was no link between omega-3 fatty acids consumption and cancer. In those with advanced cancer and cachexia, omega-3 fatty acids supplements may be of benefit, improving appetite, weight, there is tentative evidence that marine omega-3 polyunsaturated fatty acids reduce the risk of breast cancer but this is not conclusive. The effect of consumption on cancer is not conclusive. There is a risk with higher blood levels of DPA. Evidence, in the population generally, does not support a role for omega-3 fatty acid supplementation in preventing cardiovascular disease or stroke. No protective effect against the development of stroke or all-cause mortality was seen in this population, eating a diet high in fish that contain long chain omega-3 fatty acids does appear to decrease the risk of stroke. Fish oil supplementation has not been shown to benefit revascularization or abnormal heart rhythms and has no effect on heart failure hospital admission rates, furthermore, fish oil supplement studies have failed to support claims of preventing heart attacks or strokes. Evidence suggests that omega-3 fatty acids modestly lower blood pressure in people with hypertension, Omega-3 fatty acids reduce blood triglyceride levels but do not significantly change the level of LDL cholesterol or HDL cholesterol in the blood. ALA does not confer the cardiovascular benefits of EPA and DHAs
20.
Polyphenol
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Polyphenols are a structural class of mainly natural, but also synthetic or semisynthetic, organic chemicals characterized by the presence of large multiples of phenol structural units. The number and characteristics of these phenol structures underlie the unique physical, chemical, examples include tannic acid and ellagitannin. The historically important chemical class of tannins is a subset of the polyphenols, the term polyphenol appears to have been in use since 1894. g. Phenyl esters, methyl phenyl ethers and O-phenyl glycosides and this definition departs from the WBSSH definition in terms of physicochemical behavior, with its lack of reference to solubility, precipitation, and complexation phenomena. The raspberry ellagitannin, on the hand, with its 14 gallic acid moieties. Individual polyphenols engage in related to both their core phenolic structures, their linkages, and types of glycosides they form. In addition, as noted above, a feature of polyphenols was their ability to form particular. As opposed to smaller phenols, polyphenols are often larger molecules deposited in cell vacuoles, hence, many larger polyphenols are biosynthesized in-situ from smaller polyphenols to nonhydrolyzable tannins and remain undiscovered in the plant matrix. Most polyphenols contain repeating phenolic moieties of pyrocatechol, resorcinol, pyrogallol, proanthocyanidins are mostly polymeric units of catechin and epicatechin. The phenolic substructures arise from various biosynthetic pathways, especially phenylpropanoid and polyketide branches aimed at plant, in these, diverse biosynthetic steps abound, the seven-atom ring appearing in theaflavin structure above is an example of a carbocycle that is of a nonbenzenoid aromatic tropolone type. Because of the preponderance of saccharide-derived core structures, as well as spiro- and other structure types, the total synthesis of a fully unmasked polyphenol, that of the ellagitannin tellimagrandin I, was a diastereoselective sequence reported in 1994 by Feldman, Ensel and Minard. Khanbabaee and Grosser accomplished a relatively efficient total synthesis of pedunculagin in 2003, work proceeded with focus on enantioselective total syntheses, e. g. A biomimetic synthesis, and the first formal total synthesis 5-O-Desgalloyl-epi-punicacortein A, the novel strategies and methods referred to in these recent examples helped to open the field of polyphenol chemical synthesis to an unprecedented degree. They are reactive species toward oxidation, ABTS may be used to characterise polyphenol oxidation products. Polyphenols also characteristically possess a significant binding affinity for proteins, which can lead to the formation of soluble and insoluble protein-polyphenol complexes, some polyphenols are traditionally used as dyes. For instance, in the Indian subcontinent, the peel, high in tannins and other polyphenols. The aims are generally to use of plant residues from grape. Cashew nut shell liquid is an important phenolic raw material containing mostly cardol, cardanol, pyrogallol and pyrocatechin are among the oldest photographic developers
21.
Alchemy
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Alchemy is a philosophical and protoscientific tradition practiced throughout Europe, Egypt and Asia. It aimed to purify, mature, and perfect certain objects, the perfection of the human body and soul was thought to permit or result from the alchemical magnum opus and, in the Hellenistic and western tradition, the achievement of gnosis. In Europe, the creation of a stone was variously connected with all of these projects. In English, the term is limited to descriptions of European alchemy, but similar practices existed in the Far East, the Indian subcontinent. In Europe, following the 12th-century Renaissance produced by the translation of Islamic works on science, Islamic and European alchemists developed a structure of basic laboratory techniques, theory, terminology, and experimental method, some of which are still in use today. However, they continued antiquitys belief in four elements and guarded their work in secrecy including cyphers and their work was guided by Hermetic principles related to magic, mythology, and religion. The latter interests historians of esotericism, psychologists, and some philosophers, the subject has also made an ongoing impact on literature and the arts. The word alchemy was borrowed from Old French alquemie, alkimie, taken from Medieval Latin alchymia, the Arabic word is borrowed from Late Greek chēmeía, chēmía, with the agglutination of the Arabic definite article al-. This ancient Greek word was derived from the early Greek name for Egypt, Chēmia, based on the Egyptian name for Egypt, the Medieval Latin form was influenced by Greek chymeia meaning ‘mixture’ and referring to pharmaceutical chemistry. Alchemy covers several philosophical traditions spanning some four millennia and three continents and these traditions general penchant for cryptic and symbolic language makes it hard to trace their mutual influences and genetic relationships. It is still a question whether these three strands share a common origin, or to what extent they influenced each other. Here, elements of technology, religion, mythology, and Hellenistic philosophy, each with their own much longer histories, Zosimos of Panopolis wrote the oldest known books on alchemy, while Mary the Jewess is credited as being the first non-fictitious Western alchemist. They wrote in Greek and lived in Egypt under Roman rule, mythology – Zosimos of Panopolis asserted that alchemy dated back to Pharaonic Egypt where it was the domain of the priestly class, though there is little to no evidence for his assertion. Alchemical writers used Classical figures from Greek, Roman, and Egyptian mythology to illuminate their works and these included the pantheon of gods related to the Classical planets, Isis, Osiris, Jason, and many others. The central figure in the mythology of alchemy is Hermes Trismegistus and his name is derived from the god Thoth and his Greek counterpart Hermes. Hermes and his caduceus or serpent-staff, were among alchemys principal symbols, according to Clement of Alexandria, he wrote what were called the forty-two books of Hermes, covering all fields of knowledge. The Hermetica of Thrice-Great Hermes is generally understood to form the basis for Western alchemical philosophy and practice and these writings were collected in the first centuries of the common era. Technology – The dawn of Western alchemy is sometimes associated with that of metallurgy, Many writings were lost when the emperor Diocletian ordered the burning of alchemical books after suppressing a revolt in Alexandria
22.
Antoine Lavoisier
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Antoine-Laurent de Lavoisier was a French nobleman and chemist central to the 18th-century chemical revolution and had a large influence on both the history of chemistry and the history of biology. He is widely considered in popular literature as the father of modern chemistry and it is generally accepted that Lavoisiers great accomplishments in chemistry largely stem from his changing the science from a qualitative to a quantitative one. Lavoisier is most noted for his discovery of the role oxygen plays in combustion and he recognized and named oxygen and hydrogen and opposed the phlogiston theory. Lavoisier helped construct the system, wrote the first extensive list of elements. He predicted the existence of silicon and was also the first to establish that sulfur was an element rather than a compound and he discovered that, although matter may change its form or shape, its mass always remains the same. Lavoisier was a member of a number of aristocratic councils. All of these political and economic activities enabled him to fund his scientific research, at the height of the French Revolution, he was accused by Jean-Paul Marat of selling adulterated tobaccoand of other crimes, and was eventually guillotined a year after Marats death. Antoine-Laurent Lavoisier was born to a family of the nobility in Paris on 26 August 1743. The son of an attorney at the Parliament of Paris, he inherited a fortune at the age of five with the passing of his mother. Lavoisier began his schooling at the Collège des Quatre-Nations, University of Paris in Paris in 1754 at the age of 11, in his last two years at the school, his scientific interests were aroused, and he studied chemistry, botany, astronomy, and mathematics. Lavoisier entered the school of law, where he received a degree in 1763. Lavoisier received a law degree and was admitted to the bar, however, he continued his scientific education in his spare time. Lavoisiers education was filled with the ideals of the French Enlightenment of the time and he attended lectures in the natural sciences. Lavoisiers devotion and passion for chemistry were largely influenced by Étienne Condillac and his first chemical publication appeared in 1764. From 1763 to 1767, he studied geology under Jean-Étienne Guettard, in collaboration with Guettard, Lavoisier worked on a geological survey of Alsace-Lorraine in June 1767. In 1768 Lavoisier received an appointment to the Academy of Sciences. In 1769, he worked on the first geological map of France, on behalf of the Ferme générale Lavoisier commissioned the building of a wall around Paris so that customs duties could be collected from those transporting goods into and out of the city. Lavoisier attempted to introduce reforms in the French monetary and taxation system to help the peasants, Lavoisier consolidated his social and economic position when, in 1771 at age 28, he married Marie-Anne Pierrette Paulze, the 13-year-old daughter of a senior member of the Ferme générale
23.
Chemical element
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A chemical element or element is a species of atoms having the same number of protons in their atomic nuclei. There are 118 elements that have identified, of which the first 94 occur naturally on Earth with the remaining 24 being synthetic elements. There are 80 elements that have at least one stable isotope and 38 that have exclusively radioactive isotopes, iron is the most abundant element making up Earth, while oxygen is the most common element in the Earths crust. Chemical elements constitute all of the matter of the universe. The two lightest elements, hydrogen and helium, were formed in the Big Bang and are the most common elements in the universe. The next three elements were formed mostly by cosmic ray spallation, and are rarer than those that follow. Formation of elements with from 6 to 26 protons occurred and continues to occur in main sequence stars via stellar nucleosynthesis, the high abundance of oxygen, silicon, and iron on Earth reflects their common production in such stars. The term element is used for atoms with a number of protons as well as for a pure chemical substance consisting of a single element. A single element can form multiple substances differing in their structure, when different elements are chemically combined, with the atoms held together by chemical bonds, they form chemical compounds. Only a minority of elements are found uncombined as relatively pure minerals, among the more common of such native elements are copper, silver, gold, carbon, and sulfur. All but a few of the most inert elements, such as gases and noble metals, are usually found on Earth in chemically combined form. While about 32 of the elements occur on Earth in native uncombined forms. For example, atmospheric air is primarily a mixture of nitrogen, oxygen, and argon, the history of the discovery and use of the elements began with primitive human societies that found native elements like carbon, sulfur, copper and gold. Later civilizations extracted elemental copper, tin, lead and iron from their ores by smelting, using charcoal, alchemists and chemists subsequently identified many more, almost all of the naturally occurring elements were known by 1900. Save for unstable radioactive elements with short half-lives, all of the elements are available industrially, almost all other elements found in nature were made by various natural methods of nucleosynthesis. On Earth, small amounts of new atoms are produced in nucleogenic reactions, or in cosmogenic processes. Of the 94 naturally occurring elements, those with atomic numbers 1 through 82 each have at least one stable isotope, Isotopes considered stable are those for which no radioactive decay has yet been observed. Elements with atomic numbers 83 through 94 are unstable to the point that radioactive decay of all isotopes can be detected, the very heaviest elements undergo radioactive decay with half-lives so short that they are not found in nature and must be synthesized
24.
France
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France, officially the French Republic, is a country with territory in western Europe and several overseas regions and territories. The European, or metropolitan, area of France extends from the Mediterranean Sea to the English Channel and the North Sea, Overseas France include French Guiana on the South American continent and several island territories in the Atlantic, Pacific and Indian oceans. France spans 643,801 square kilometres and had a population of almost 67 million people as of January 2017. It is a unitary republic with the capital in Paris. Other major urban centres include Marseille, Lyon, Lille, Nice, Toulouse, during the Iron Age, what is now metropolitan France was inhabited by the Gauls, a Celtic people. The area was annexed in 51 BC by Rome, which held Gaul until 486, France emerged as a major European power in the Late Middle Ages, with its victory in the Hundred Years War strengthening state-building and political centralisation. During the Renaissance, French culture flourished and a colonial empire was established. The 16th century was dominated by civil wars between Catholics and Protestants. France became Europes dominant cultural, political, and military power under Louis XIV, in the 19th century Napoleon took power and established the First French Empire, whose subsequent Napoleonic Wars shaped the course of continental Europe. Following the collapse of the Empire, France endured a succession of governments culminating with the establishment of the French Third Republic in 1870. Following liberation in 1944, a Fourth Republic was established and later dissolved in the course of the Algerian War, the Fifth Republic, led by Charles de Gaulle, was formed in 1958 and remains to this day. Algeria and nearly all the colonies became independent in the 1960s with minimal controversy and typically retained close economic. France has long been a centre of art, science. It hosts Europes fourth-largest number of cultural UNESCO World Heritage Sites and receives around 83 million foreign tourists annually, France is a developed country with the worlds sixth-largest economy by nominal GDP and ninth-largest by purchasing power parity. In terms of household wealth, it ranks fourth in the world. France performs well in international rankings of education, health care, life expectancy, France remains a great power in the world, being one of the five permanent members of the United Nations Security Council with the power to veto and an official nuclear-weapon state. It is a member state of the European Union and the Eurozone. It is also a member of the Group of 7, North Atlantic Treaty Organization, Organisation for Economic Co-operation and Development, the World Trade Organization, originally applied to the whole Frankish Empire, the name France comes from the Latin Francia, or country of the Franks
25.
Louis-Bernard Guyton de Morveau
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Louis-Bernard Guyton, Baron de Morveau was a French chemist and politician. He is credited with producing the first systematic method of chemical nomenclature, Guyton de Morveau was born in Dijon, where he served as a lawyer, then avocat général, of the Dijon parlement. In 1773, already interested in chemistry, he proposed use of acid gas for fumigation of buildings. However, chlorine was not well characterized at that time, in 1782 he resigned this post to dedicate himself to chemistry, collaborating on the Encyclopédie Méthodique and working for industrial applications. He performed various services in this role, and founded La Société des Mines et Verreries in Saint-Bérain-sur-Dheune. He developed the first system of chemical nomenclature, in 1783, he was elected a foreign member of the Royal Swedish Academy of Sciences and in 1788 a Fellow of the Royal Society. Although a member of the wing, he voted in favor of the execution of King Louis XVI. He himself flew in a balloon during the battle of Fleurus on 26 June 1794 and he was among the founders of the École Polytechnique and the École de Mars, and was a professor of mineralogy at the Polytechnique. He became a member of the Académie des sciences in chemistry, on 20 November 1795. In 1798 he married Claudine Picardet, a widowed friend. Under the Directory, he served on the Council of Five Hundred from 1797, elected from Ille-et-Vilaine, with Hugues Maret and Jean François Durande he also published the Élémens de chymie théorique et pratique. During his lifetime, Guyton de Morveau received the cross of the Legion of Honour and was made an Officer of the Legion of Honour for service to humanity and he was made a baron of the First French Empire in 1811. Guyton de Morveau died in Paris on 2 January 1816
26.
Berthollet
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Claude Louis Berthollet was a Savoyard-French chemist who became vice president of the French Senate in 1804. He is known for his contributions to theory of chemical equilibria via the mechanism of reverse chemical reactions. On a practical basis, Berthollet was the first to demonstrate the action of chlorine gas. Claude Louis Berthollet was born in Talloires, near Annecy, then part of the Duchy of Savoy and he started his studies at Chambéry and then in Turin where he graduated in medicine. Berthollets great new developments in works regarding chemistry made him, in a period of time. Berthollet, along with Antoine Lavoisier and others, devised a chemical nomenclature, or a system of names and he also carried out research into dyes and bleaches, being first to introduce the use of chlorine gas as a commercial bleach in 1785. He first produced a modern bleaching liquid in 1789 in his laboratory on the quay Javel in Paris, France, the resulting liquid, known as Eau de Javel, was a weak solution of sodium hypochlorite. Another strong chlorine oxidant and bleach which he investigated and was the first to produce, Berthollet first determined the elemental composition of the gas ammonia, in 1785. Berthollet was one of the first chemists to recognize the characteristics of a reverse reaction, Berthollet was engaged in a long-term battle with another French chemist Joseph Proust on the validity of the law of definite proportions. Although Proust proved his theory by accurate measurements, his theory was not immediately accepted partially due to Berthollets authority and his law was finally accepted when Berzelius confirmed it in 1811. But it was later that Berthollet was not completely wrong because there exists a class of compounds that do not obey the law of definite proportions. These non-stoichiometric compounds are also named berthollides in his honor, Berthollet was one of several scientists who went with Napoleon to Egypt, and was a member of the physics and natural history section of the Institut dÉgypte. In April,1789 Berthollet was elected a Fellow of the Royal Society of London, in 1801, he was elected a foreign member of the Royal Swedish Academy of Sciences. In 1809, Berthollet was elected a member first class of the Royal Institute of the Netherlands, predecessor of the Royal Netherlands Academy of Arts. He was elected an Honorary Fellow of the Royal Society of Edinburgh in 1820, Berthollet married Marguerite Baur in 1788. Berthollet was an accused of being an atheist and he died in Arcueil, France in 1822. Society of the Friends of Truth Satish, Kapoor, zeitschrift für anorganische und allgemeine Chemie. Between science and craft, The case of berthollet and dyeing, zeitschrift für anorganische und allgemeine Chemie
27.
Guillotine
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A guillotine is an apparatus designed for efficiently carrying out executions by beheading. The device consists of a tall, upright frame in which a weighted and angled blade is raised to the top, the condemned person is secured with stocks at the bottom of the frame, positioning the neck directly below the blade. The blade is released, to fall swiftly and forcefully decapitating the victim with a single pass so that the head falls into a basket below. The name dates from period, but similar devices had been used elsewhere in Europe over several centuries. The guillotine continued to be used long after the revolution and remained Frances standard method of execution until the abolition of capital punishment in 1981. The last person to be executed in France was Hamida Djandoubi, the use of beheading machines in Europe long predates such use in the French revolution in 1792. An early example of the principle is found in the High History of the Holy Grail, although the device is imaginary, its function is clear. The text says, Within these three openings are the set for them. And behold what I would do to them if their three heads were therein, even thus will I cut off their heads when they shall set them into those three openings thinking to adore the hallows that are beyond. The Halifax Gibbet was a structure of two wooden uprights, capped by a horizontal beam, of a total height of 4.5 metres. The blade was an axe head weighing 3.5 kg, attached to the bottom of a wooden block that slid up. This device was mounted on a square platform 1.25 metres high. It is not known when the Halifax Gibbet was first used, the first recorded execution in Halifax dates from 1280, the machine remained in use until Oliver Cromwell forbade capital punishment for petty theft. It was used for the last time, for the execution of two criminals on a day, on 30 April 1650. Holinsheds Chronicles of 1577 included a picture of The execution of Murcod Ballagh near to Merton in Ireland 1307 showing a similar execution machine, the Maiden was constructed in 1564 for the Provost and Magistrates of Edinburgh, and was in use from April 1565 to 1710. One of those executed was James Douglas, 4th Earl of Morton, in 1581, Schmidt recommended using an angled blade as opposed to a round one. On 10 October 1789, physician Joseph-Ignace Guillotin proposed to the National Assembly that capital punishment always take the form of decapitation by means of a simple mechanism, sensing the growing discontent, Louis XVI banned the use of the breaking wheel. A committee was formed under Antoine Louis, physician to the King, Guillotin was also on the committee
28.
Geneva
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Geneva is the second most populous city in Switzerland and is the most populous city of Romandy, the French-speaking part of Switzerland. Situated where the Rhône exits Lake Geneva, it is the capital of the Republic, the municipality has a population of 198,072, and the canton has 484,736 residents. In 2014, the compact agglomération du Grand Genève had 946,000 inhabitants in 212 communities in both Switzerland and France, within Swiss territory, the commuter area named Métropole lémanique contains a population of 1.25 million. This area is essentially spread east from Geneva towards the Riviera area and north-east towards Yverdon-les-Bains, Geneva is the city that hosts the highest number of international organizations in the world. It is also the place where the Geneva Conventions were signed, Geneva was ranked as the worlds ninth most important financial centre for competitiveness by the Global Financial Centres Index, ahead of Frankfurt, and third in Europe behind London and Zürich. A2009 survey by Mercer found that Geneva has the third-highest quality of life of any city in the world, the city has been referred to as the worlds most compact metropolis and the Peace Capital. In 2009 and 2011, Geneva was ranked as, respectively, the city was mentioned in Latin texts, by Caesar, with the spelling Genava, probably from a Celtic toponym *genawa- from the stem *genu-, in the sense of a bending river or estuary. The medieval county of Geneva in Middle Latin was known as pagus major Genevensis or Comitatus Genevensis, the name takes various forms in modern languages, Geneva /dʒᵻˈniːvə/ in English, French, Genève, German, Genf, Italian, Ginevra, and Romansh, Genevra. The city in origin shares its name, *genawa estuary, with the Italian port city of Genoa, Geneva was an Allobrogian border town, fortified against the Helvetii tribe, when the Romans took it in 121 BC. It became Christian under the Late Roman Empire, and acquired its first bishop in the 5th century, having been connected to the bishopric of Vienne in the 4th. In the Middle Ages, Geneva was ruled by a count under the Holy Roman Empire until the late 14th century, around this time the House of Savoy came to dominate the city. In the 15th century, a republican government emerged with the creation of the Grand Council. In 1541, with Protestantism in the ascendancy, John Calvin, by the 18th century, however, Geneva had come under the influence of Catholic France, which cultivated the city as its own. France also tended to be at odds with the ordinary townsfolk, in 1798, revolutionary France under the Directory annexed Geneva. At the end of the Napoleonic Wars, on 1 June 1814, in 1907, the separation of Church and State was adopted. Geneva flourished in the 19th and 20th centuries, becoming the seat of international organizations. Geneva is located at 46°12 North, 6°09 East, at the end of Lake Geneva. It is surrounded by two chains, the Alps and the Jura
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World War I
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World War I, also known as the First World War, the Great War, or the War to End All Wars, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918. More than 70 million military personnel, including 60 million Europeans, were mobilised in one of the largest wars in history and it was one of the deadliest conflicts in history, and paved the way for major political changes, including revolutions in many of the nations involved. The war drew in all the worlds great powers, assembled in two opposing alliances, the Allies versus the Central Powers of Germany and Austria-Hungary. These alliances were reorganised and expanded as more nations entered the war, Italy, Japan, the trigger for the war was the assassination of Archduke Franz Ferdinand of Austria, heir to the throne of Austria-Hungary, by Yugoslav nationalist Gavrilo Princip in Sarajevo on 28 June 1914. This set off a crisis when Austria-Hungary delivered an ultimatum to the Kingdom of Serbia. Within weeks, the powers were at war and the conflict soon spread around the world. On 25 July Russia began mobilisation and on 28 July, the Austro-Hungarians declared war on Serbia, Germany presented an ultimatum to Russia to demobilise, and when this was refused, declared war on Russia on 1 August. Germany then invaded neutral Belgium and Luxembourg before moving towards France, after the German march on Paris was halted, what became known as the Western Front settled into a battle of attrition, with a trench line that changed little until 1917. On the Eastern Front, the Russian army was successful against the Austro-Hungarians, in November 1914, the Ottoman Empire joined the Central Powers, opening fronts in the Caucasus, Mesopotamia and the Sinai. In 1915, Italy joined the Allies and Bulgaria joined the Central Powers, Romania joined the Allies in 1916, after a stunning German offensive along the Western Front in the spring of 1918, the Allies rallied and drove back the Germans in a series of successful offensives. By the end of the war or soon after, the German Empire, Russian Empire, Austro-Hungarian Empire, national borders were redrawn, with several independent nations restored or created, and Germanys colonies were parceled out among the victors. During the Paris Peace Conference of 1919, the Big Four imposed their terms in a series of treaties, the League of Nations was formed with the aim of preventing any repetition of such a conflict. This effort failed, and economic depression, renewed nationalism, weakened successor states, and feelings of humiliation eventually contributed to World War II. From the time of its start until the approach of World War II, at the time, it was also sometimes called the war to end war or the war to end all wars due to its then-unparalleled scale and devastation. In Canada, Macleans magazine in October 1914 wrote, Some wars name themselves, during the interwar period, the war was most often called the World War and the Great War in English-speaking countries. Will become the first world war in the sense of the word. These began in 1815, with the Holy Alliance between Prussia, Russia, and Austria, when Germany was united in 1871, Prussia became part of the new German nation. Soon after, in October 1873, German Chancellor Otto von Bismarck negotiated the League of the Three Emperors between the monarchs of Austria-Hungary, Russia and Germany
30.
IUPAC nomenclature of organic chemistry
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It is published in the Nomenclature of Organic Chemistry. Ideally, every possible organic compound should have a name from which a structural formula can be created. There is also an IUPAC nomenclature of inorganic chemistry, otherwise the common or trivial name may be used, often derived from the source of the compound. In addition, very long names may be less concise than structural formulae, in chemistry, a number of prefixes, suffixes and infixes are used to describe the type and position of functional groups in the compound. The steps for naming an organic compound are, Identification of the parent hydrocarbon chain and this chain must obey the following rules, in order of precedence, It should have the maximum number of substituents of the suffix functional group. By suffix, it is meant that the parent functional group should have a suffix, if more than one functional group is present, the one with highest precedence should be used. It should have the number of multiple bonds It should have the maximum number of single bonds. It should have the maximum length, Identification of the parent functional group, if any, with the highest order of precedence. Side chains are the chains that are not in the parent chain. Identification of the functional groups, if any, and naming them by their ionic prefixes. Different side-chains and functional groups will be grouped together in alphabetical order, when both side chains and secondary functional groups are present, they should be written mixed together in one group rather than in two separate groups. Locants are the numbers on the carbons to which the substituent is directly attached, has the lowest-numbered locants for multiple bonds. Has the lowest-numbered locants for prefixes, numbering of the various substituents and bonds with their locants. If there are two side-chains with the alpha carbon, the number will be written twice. If there are double bonds and triple bonds, en is written before yne. When the main group is a terminal functional group, there is no need to number it. Wherever it says with numbers, it is understood that between the word and the numbers, the prefix is used. Adding of punctuation, Commas are put between numbers Hyphens are put between a number and a letter Successive words are merged into one word Note, IUPAC uses one-word names throughout and this is why all parts are connected
31.
Ionic compound
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In chemistry, an ionic compound is a chemical compound composed of ions held together by electrostatic forces termed ionic bonding. The compound is overall, but consists of positively charged ions called cations. These can be simple ions such as the sodium and chloride in sodium chloride, or polyatomic species such as the ammonium, Ionic compounds containing hydrogen ions are classified as acids, and those containing basic ions hydroxide or oxide are classified as bases. Ionic compounds without these ions are known as salts and can be formed by acid–base reactions. Ionic compounds typically have high melting and boiling points, and are hard, as solids they are almost always electrically insulating, but when melted or dissolved they become highly conductive, because the ions are mobilized. The word ion is the Greek ἰόν, ion, going and this term was introduced by English physicist and chemist Michael Faraday in 1834 for the then-unknown species that goes from one electrode to the other through an aqueous medium. In 1913 the crystal structure of sodium chloride was determined by William Henry Bragg, many other inorganic compounds were also found to have similar structural features. Principal contributors to the development of a treatment of ionic crystal structures were Max Born, Fritz Haber, Alfred Landé, Erwin Madelung, Paul Peter Ewald. Born predicted crystal energies based on the assumption of ionic constituents, Ionic compounds can be produced from their constituent ions by evaporation, precipitation, or freezing. Reactive metals such as the alkali metals can react directly with the highly electronegative halogen gases to form an ionic product and they can also be synthesized as the product of a high temperature reaction between solids. If the ionic compound is soluble in a solvent, it can be obtained as a compound by evaporating the solvent from this electrolyte solution. This process occurs widely in nature, and is the means of formation of the evaporite minerals, insoluble ionic compounds can be precipitated by mixing two solutions, one with the cation and one with the anion in it. Because all solutions are neutral, the two solutions mixed must also contain counterions of the opposite charges. To ensure that these do not contaminate the precipitated ionic compound, if the two solutions have hydrogen ions and hydroxide ions as the counterions, they will react with one another in what is called an acid–base reaction or a neutralization reaction to form water. Alternately the counterions can be chosen to ensure that even when combined into a solution they will remain soluble as spectator ions. Molten salts will solidify on cooling to below their freezing point and this is sometimes used for the solid-state synthesis of complex ionic compounds from solid reactants, which are first melted together. In other cases the solid reactants do not need to be melted, other synthetic routes use a solid precursor with the correct stoichiometric ratio of non-volatile ions, which is heated to drive off other species. There is also an additional attractive force from van der Waals interactions which contributes only around 1–2% of the cohesive energy for small ions
