Portal:Chemistry


Introduction

Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and compounds made of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during reactions with other substances. Chemistry also addresses the nature of chemical bonds in chemical compounds.

In the scope of its subject, chemistry occupies an intermediate position between physics and biology. It is sometimes called the central science because it provides a foundation for understanding both basic and applied scientific disciplines at a fundamental level. For example, chemistry explains aspects of plant growth (botany), the formation of igneous rocks (geology), how atmospheric ozone is formed and how environmental pollutants are degraded (ecology), the properties of the soil on the Moon (cosmochemistry), how medications work (pharmacology), and how to collect DNA evidence at a crime scene (forensics).

Chemistry has existed under various names since ancient times. It has evolved, and now chemistry encompasses various areas of specialisation, or subdisciplines, that continue to increase in number and interrelate to create further interdisciplinary fields of study. The applications of various fields of chemistry are used frequently for economic purposes in the chemical industry. (Full article...)

Selected article

Detail of acetic acid crystals
Acetic acid (CH3COOH), also known as ethanoic acid, is an organic chemical compound best recognized for giving vinegar its sour taste and pungent smell. Pure water-free acetic acid is a colourless hygroscopic liquid (that is, it readily absorbs water) that freezes below 16.7 °C (62 °F) to a colourless crystalline solid. Acetic acid is corrosive, and its vapour is irritating to eyes and nose, although it is a weak acid based on its ability to dissociate in aqueous solutions.

Acetic acid is one of the simplest carboxylic acids. It is an important chemical reagent and industrial chemical that is used in the production of polyethylene terephthalate mainly in soft drink bottles; cellulose acetate, mainly for photographic film; and polyvinyl acetate for wood glue, as well as many synthetic fibres and fabrics. In households diluted acetic acid is often used in descaling agents. In the food industry acetic acid is used under the food additive code E260 as an acidity regulator.

The global demand for acetic acid is around 6.5 million tonnes per year (Mt/a), of which approximately 1.5 Mt/a is met by recycling; the remainder is manufactured from petrochemical feedstocks or from biological sources.

Subcategories

History and Philosophy of Chemistry

Antoine Lavoisier
Antoine Lavoisier

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.

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.

unit-conversion.info A good 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.

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.

ABC-Chemistry A directory of free full-text journals in chemistry, biochemistry and related subjects.

The Element Song A goofy little song about all of the elements.

Selected image

Malachite
Malachite
Malachite is a carbonate mineral, copper(II) carbonate hydroxide Cu2CO3(OH)2. It crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses. Its beauty may be seen most strikingly in the Malachite Room at the Hermitage in Saint Petersburg.

Selected biography

Hermann Emil Fischer
Hermann Emil Fischer (1852-1919) was a German chemist, and recipient of the Nobel Prize in Chemistry in 1902. Many consider Fischer to be the most brilliant chemist who ever lived, because of his numerous contributions to science, especially chemistry and biochemistry. Among these is his discovery of phenylhydrazine. He also undertook vast studies on purines. This work showed that various substances such as adenine, xanthine, caffeine, uric acid, and guanine, all belonged to one homogeneous family, and could be derived from one another. He reasoned this to be due to their common origins from a parent molecule, a bicyclic nitrogenous structure into which the characteristic urea group entered. Fischer regarded this structure as hypothetical, and named it 'purine' in 1884. He synthesised it in 1898. He is also famed for his work on sugars.

Techniques used by chemists

Equipment used by chemists

Chemistry in society

Chemistry in industry

WikiProjects

Topics

Periodic Table

Group 1 2   3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Hydrogen &
alkali metals
Alkaline earth metals Triels Tetrels Pnicto­gens Chal­co­gens Halo­gens Noble
gases
Period

1

Hydro­gen1H1.0080 He­lium2He4.0026
2 Lith­ium3Li6.94 Beryl­lium4Be9.0122 Boron5B10.81 Carbon6C12.011 Nitro­gen7N14.007 Oxy­gen8O15.999 Fluor­ine9F18.998 Neon10Ne20.180
3 So­dium11Na22.990 Magne­sium12Mg24.305 Alumin­ium13Al26.982 Sili­con14Si28.085 Phos­phorus15P30.974 Sulfur16S32.06 Chlor­ine17Cl35.45 Argon18Ar39.95
4 Potas­sium19K39.098 Cal­cium20Ca40.078 Scan­dium21Sc44.956 Tita­nium22Ti47.867 Vana­dium23V50.942 Chrom­ium24Cr51.996 Manga­nese25Mn54.938 Iron26Fe55.845 Cobalt27Co58.933 Nickel28Ni58.693 Copper29Cu63.546 Zinc30Zn65.38 Gallium31Ga69.723 Germa­nium32Ge72.630 Arsenic33As74.922 Sele­nium34Se78.971 Bromine35Br79.904 Kryp­ton36Kr83.798
5 Rubid­ium37Rb85.468 Stront­ium38Sr87.62 Yttrium39Y88.906 Zirco­nium40Zr91.224 Nio­bium41Nb92.906 Molyb­denum42Mo95.95 Tech­netium43Tc​[97] Ruthe­nium44Ru101.07 Rho­dium45Rh102.91 Pallad­ium46Pd106.42 Silver47Ag107.87 Cad­mium48Cd112.41 Indium49In114.82 Tin50Sn118.71 Anti­mony51Sb121.76 Tellur­ium52Te127.60 Iodine53I126.90 Xenon54Xe131.29
6 Cae­sium55Cs132.91 Ba­rium56Ba137.33 1 asterisk Lute­tium71Lu174.97 Haf­nium72Hf178.49 Tanta­lum73Ta180.95 Tung­sten74W183.84 Rhe­nium75Re186.21 Os­mium76Os190.23 Iridium77Ir192.22 Plat­inum78Pt195.08 Gold79Au196.97 Mer­cury80Hg200.59 Thallium81Tl204.38 Lead82Pb207.2 Bis­muth83Bi208.98 Polo­nium84Po​[209] Asta­tine85At​[210] Radon86Rn​[222]
7 Fran­cium87Fr​[223] Ra­dium88Ra​[226] 1 asterisk Lawren­cium103Lr​[266] Ruther­fordium104Rf​[267] Dub­nium105Db​[268] Sea­borgium106Sg​[269] Bohr­ium107Bh​[270] Has­sium108Hs​[271] Meit­nerium109Mt​[278] Darm­stadtium110Ds​[281] Roent­genium111Rg​[282] Coper­nicium112Cn​[285] Nihon­ium113Nh​[286] Flerov­ium114Fl​[289] Moscov­ium115Mc​[290] Liver­morium116Lv​[293] Tenness­ine117Ts​[294] Oga­nesson118Og​[294]
1 asterisk Lan­thanum57La138.91 Cerium58Ce140.12 Praseo­dymium59Pr140.91 Neo­dymium60Nd144.24 Prome­thium61Pm​[145] Sama­rium62Sm150.36 Europ­ium63Eu151.96 Gadolin­ium64Gd157.25 Ter­bium65Tb158.93 Dyspro­sium66Dy162.50 Hol­mium67Ho164.93 Erbium68Er167.26 Thulium69Tm168.93 Ytter­bium70Yb173.05  
1 asterisk Actin­ium89Ac​[227] Thor­ium90Th232.04 Protac­tinium91Pa231.04 Ura­nium92U238.03 Neptu­nium93Np​[237] Pluto­nium94Pu​[244] Ameri­cium95Am​[243] Curium96Cm​[247] Berkel­ium97Bk​[247] Califor­nium98Cf​[251] Einstei­nium99Es​[252] Fer­mium100Fm​[257] Mende­levium101Md​[258] Nobel­ium102No​[259]

Associated Wikimedia

The following Wikimedia Foundation sister projects provide more on this subject:

Sources

  1. ^ Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–291. doi:10.1515/pac-2015-0305.
  2. ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
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