Portal:Chemistry

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The Chemistry Portal

Welcome to the chemistry portal. Chemistry, from Greek language χυμεία meaning "study of liquids", is a branch of science. Modern chemistry focuses on the study of elements of the world and the bonds between elements. Chemistry also deals with composition, structure, and properties of substances and the transformations that they undergo. In the study of matter, chemistry also investigates its interactions with energy and itself. Because of the diversity of matter, which is mostly in the form of compounds, chemists often study how atoms of different chemical elements interact to form molecules, and how molecules interact with each other.

Portal navigation Featured article - Selected picture - News - Selected biography - History and Philosophy - Techniques - Equipment - Chemistry in society - Chemistry in industry - Periodic Table - Resources - WikiProjects - Things you can do - Collaboration of the month - Related portals - Associated Wikimedia

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Featured article

The cyclol hypothesis was the first structural model of a folded, globular protein. It was developed by Dorothy Wrinch in the late 1930's, and was based on three assumptions. Firstly, the hypothesis assumes that two peptide groups can be crosslinked by a cyclol reaction; these crosslinks are covalent analogs of non-covalent hydrogen bonds between peptide groups. These reactions have been observed in the ergopeptides and other compounds. Secondly, it assumes that, under some conditions, amino acids will naturally make the maximum possible number of cyclol crosslinks, resulting in cyclol molecules and cyclol fabrics. Finally, the hypothesis assumes that globular proteins have a tertiary structure corresponding to Platonic solids and semiregular polyhedra formed of cyclol fabrics with no free edges.

Although incorrect as a model for the structure of globular proteins, several elements of the cyclol model were later verified, such as the cyclol reaction itself and the hypothesis that hydrophobic interactions are chiefly responsible for protein folding. The cyclol hypothesis stimulated many scientists to research questions in protein structure and chemistry, and was a precursor of the more accurate models hypothesized for the DNA double helix and protein secondary structure. The proposal and testing of the cyclol model also provides an excellent illustration of empirical falsifiability acting as part of the scientific method.

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Selected picture

Credit: User:Mstroeck

Allotropy is the ability of a chemical to exhibit a number of different and physically distinct forms in its pure elemental state. The element carbon displays many allotropic forms, 8 of which are displayed here. They are (a) diamond, (b) graphite, (c) lonsdaleite, (d) buckminsterfullerene, (e) C540, (f) C70, (g) amorphous carbon and (h) a single walled carbon nanotube.

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History and Philosophy of Chemistry

Many chemists have an interest in the history of chemistry. Those with philosophical interests will be interested that the philosophy of chemistry has quite recently developed along a path somewhat different from the general philosophy of science.

Other articles that might interest you are:

There is a Wikipedia Project on the History of Science and portals for the scientific method and philosophy of science.

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Chemistry Resources

Wikipedia:WikiProject Chemicals/Data is a collection of links and references that are useful for chemistry-related works. This includes free online chemical databases, publications, patents, computer programs, and various tools.

Science is Fun University of Wisconsin-Madison Chemistry Professor Bassam Z. Shakhashiri, shares the fun of science.

megaConverter The Web's best place to figure out what equals what.

General Chemistry Online Clear text and comprehensive coverage of general chemistry topics by Fred Senese, Dept. of Chemistry Frostburg State University

General Chemistry Demonstration at Purdue Video clips (and descriptions) of lecture demonstrations.

Intota Chemistry Experts A large online listing of real-world chemistry expert biographies provides examples of the many areas of expertise and careers in chemistry.

Chemistry Webercises Directory A large listing of chemistry resources maintained by Steven Murov, Emeritus Chemistry Professor Modesto Junior College.

MathMol MathMol (Mathematics and Molecules) is a good starting point for those interested in the field of molecular modeling.

Chemistry Educational Resources and Essential References from Wiley, the world's largest chemistry publisher

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In the news

Hydrated protons pair up

2-15 Chemists modeling the structure of strongly acidic solutions have found that hydronium ions can associate into unusual ion pairs. Gregory A. Voth and Sergei Izvekov of the University of Utah, in collaboration with Feng Wang of Boston University, were examining the structure of aqueous hydrochloric acid at concentrations of 0.43-0.85 M, and they found that the ions unexpectedly associate into pairs. See doi:10.1021/ja078106i Read more...
11-28 The 103 year old Zincke reaction rediscovered by research groups from Japan and the U.S.A. German chemist Manfred Christl criticizes responsible scientists and publishers for doing sloppy work in a letter to the Angewandte Chemie: the chemistry presented is not new and the structure assignment incorrect. Read more....
10-30 Chemists from the University of Delaware, Newark, in collaboration with the University of Wisconsin-Madison, recently reported their preparation of a complex containing two chromium atoms connected by the shortest ever metal-metal bond, 1.8028 Å (0.l nm) long. It is believed to contain a quintuple bond. Read more...
10-26 Arthur Kornberg died on October 26, 2007 of respiratory failure at age 89. Kornberg was the first to isolate DNA polymerase I, for which he won the 1959 Nobel Prize in Physiology or Medicine. Read more...

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Selected biography

Louis Pasteur (1822-1895) was a French microbiologist and chemist. He was the first to demonstrate chirality of molecules, using tartaric acid crystals, but this achievement is often overlooked in favor of his more famous work in biology and medicine. He is best known for demonstrating how to prevent milk and wine from going sour, a process which came to be called pasteurization. His experiments confirmed the germ theory of disease, and he created the first vaccine for rabies. He became one of the main founders of bacteriology, the other major figure being Robert Koch. Pasteur also discovered anaerobiosis, whereby some microorganisms can develop and live without air or oxygen. ...Archive/Nominations

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