An Acid is a molecule or ion capable of donating a proton, or, capable of forming a covalent bond with an electron pair. The first category of acids are the Brønsted -- Lowry acids. In the special case of aqueous solutions, proton donors form the hydronium ion H3O+ and are known as Arrhenius acids. Brønsted and Lowry generalized the Arrhenius theory to include non-aqueous solvents. A Brønsted or Arrhenius acid contains a hydrogen atom bonded to a chemical structure, still energetically favorable after loss of H+. Aqueous Arrhenius acids have characteristic properties which provide a practical description of an acid. Acids form aqueous solutions with a sour taste, can turn blue litmus red, react with bases and certain metals to form salts; the word acid is derived from the Latin acidus/acēre meaning sour. An aqueous solution of an acid has a pH less than 7 and is colloquially referred to as'acid', while the strict definition refers only to the solute. A lower pH means a higher acidity, thus a higher concentration of positive hydrogen ions in the solution.
Chemicals or substances having the property of an acid are said to be acidic. Common aqueous acids include hydrochloric acid, acetic acid, sulfuric acid, citric acid; as these examples show, acids can be solutions or pure substances, can be derived from acids that are solids, liquids, or gases. Strong acids and some concentrated weak acids are corrosive, but there are exceptions such as carboranes and boric acid; the second category of acids are Lewis acids. An example is boron trifluoride, whose boron atom has a vacant orbital which can form a covalent bond by sharing a lone pair of electrons on an atom in a base, for example the nitrogen atom in ammonia. Lewis considered this as a generalization of the Brønsted definition, so that an acid is a chemical species that accepts electron pairs either directly or by releasing protons into the solution, which accept electron pairs. However, hydrogen chloride, acetic acid, most other Brønsted-Lowry acids cannot form a covalent bond with an electron pair and are therefore not Lewis acids.
Conversely, many Lewis acids are not Brønsted-Lowry acids. In modern terminology, an acid is implicitly a Brønsted acid and not a Lewis acid, since chemists always refer to a Lewis acid explicitly as a Lewis acid. Modern definitions are concerned with the fundamental chemical reactions common to all acids. Most acids encountered in everyday life are aqueous solutions, or can be dissolved in water, so the Arrhenius and Brønsted-Lowry definitions are the most relevant; the Brønsted-Lowry definition is the most used definition. Hydronium ions are acids according to all three definitions. Although alcohols and amines can be Brønsted-Lowry acids, they can function as Lewis bases due to the lone pairs of electrons on their oxygen and nitrogen atoms; the Swedish chemist Svante Arrhenius attributed the properties of acidity to hydrogen ions or protons in 1884. An Arrhenius acid is a substance that, when added to water, increases the concentration of H+ ions in the water. Note that chemists write H+ and refer to the hydrogen ion when describing acid-base reactions but the free hydrogen nucleus, a proton, does not exist alone in water, it exists as the hydronium ion, H3O+.
Thus, an Arrhenius acid can be described as a substance that increases the concentration of hydronium ions when added to water. Examples include molecular substances such as acetic acid. An Arrhenius base, on the other hand, is a substance which increases the concentration of hydroxide ions when dissolved in water; this decreases the concentration of hydronium because the ions react to form H2O molecules: H3O+ + OH− ⇌ H2O + H2ODue to this equilibrium, any increase in the concentration of hydronium is accompanied by a decrease in the concentration of hydroxide. Thus, an Arrhenius acid could be said to be one that decreases hydroxide concentration, while an Arrhenius base increases it. In an acidic solution, the concentration of hydronium ions is greater than 10−7 moles per liter. Since pH is defined as the negative logarithm of the concentration of hydronium ions, acidic solutions thus have a pH of less than 7. While the Arrhenius concept is useful for describing many reactions, it is quite limited in its scope.
In 1923 chemists Johannes Nicolaus Brønsted and Thomas Martin Lowry independently recognized that acid-base reactions involve the transfer of a proton. A Brønsted-Lowry acid is a species. Brønsted-Lowry acid-base theory has several advantages over Arrhenius theory. Consider the following reactions of acetic acid, the organic acid that gives vinegar its characteristic taste: CH3COOH + H2O ⇌ CH3COO− + H3O+ CH3COOH + NH3 ⇌ CH3COO− + NH+4Both theories describe the first reaction: CH3COOH acts as an Arrhenius acid because it acts as a source of H3O+ when dissolved in water, it acts as a Brønsted acid by donating a proton to water. In the second example CH3COOH undergoes the same transformation, in this case donating a proton to ammonia, but does not relate to the Arrhenius definition of an acid because the reaction does not produce hydronium. Nev
ISO 639-1:2002, Codes for the representation of names of languages — Part 1: Alpha-2 code, is the first part of the ISO 639 series of international standards for language codes. Part 1 covers the registration of two-letter codes. There are 184 two-letter codes registered as of December 2018; the registered codes cover the world's major languages. These codes are a useful formal shorthand for indicating languages. Many multilingual web sites—such as Wikipedia—use these codes to prefix URLs of specific language versions of their web sites: for example, en. Wikipedia.org is the English version of Wikipedia. See IETF language tag.. ISO 639, the original standard for language codes, was approved in 1967, it was split into parts, in 2002 ISO 639-1 became the new revision of the original standard. The last code added was ht, representing Haitian Creole on 2003-02-26; the use of the standard was encouraged by IETF language tags, introduced in RFC 1766 in March 1995, continued by RFC 3066 from January 2001 and RFC 4646 from September 2006.
The current version is RFC 5646 from September 2009. Infoterm is the registration authority for ISO 639-1 codes. New ISO 639-1 codes are not added if an ISO 639-2 code exists, so systems that use ISO 639-1 and 639-2 codes, with 639-1 codes preferred, do not have to change existing codes. If an ISO 639-2 code that covers a group of languages is used, it might be overridden for some specific languages by a new ISO 639-1 code. There is no specification on treatment of macrolanguages. List of ISO 639-1 codes ISO 3166-1 alpha-2, a different set of two-letter codes used for countries ISO 639 ISO 639-1/RA ISO 639-2 Registration Authority FAQ
Genie is an American company owned by Terex which manufactures work lifts and platforms used in construction, warehouse stocking, equipment installation. Founded in 1966 by Bud Bushnell, the company operated independently until acquired by Terex in 2002. Genie operates in locations worldwide, headquartered in Redmond, United States; the company marked its 50th anniversary in 2016. Genie Industries was founded in 1966 by Bud Bushnell. At the time, Bushnell was working for Seattle Bronze, a company that produced hoists in Kent, Washington. Bushnell bought the manufacturing rights to a material lift. Bushnell named the product Genie because he thought the hissing sound of the compressed air used to raise the machine's operator sounded like a genie rising from its bottle; the Genie Hoist was patented by Bushnell in 1968. In the 1970s, the company continued to grow with the addition several material-handling devices, including the Teletower and the company's first personal lift in 1978. In its early years, Genie manufactured products at a facility in Washington.
In 1982, Genie moved its headquarters to Washington. Today, the company continues to maintain its corporate headquarters, three manufacturing facilities, in Redmond. After moving to the manufacturing facility in Redmond, Genie introduced the first Z-boom in 1984. In 1993, Genie introduced the IWP; the company followed up that introduction with the addition of scissor lifts in 1997, trailer-mounted boom in 1998 and rough-terrain scissor lifts in 1999. In 1998, Genie expanded its Washington state manufacturing footprint to Moses Lake. In 2002, Genie Industries was acquired by Terex Corporation, a global manufacturer of construction and industrial equipment. In the years following the sale, the Genie organization was transitioned over to the Terex Aerial Work Platforms segment of Terex. All of the company's products are still marketed under the Genie brand; the sale of the company led to Genie expanding its manufacturing ability to other parts of the world. Genie now has manufacturing facilities in China and the United Kingdom.
The company employs more than 1,800 people in Redmond and more than 3,800 worldwide. Genie products are used in aviation, entertainment and military, industrial and retail applications; the equipment rental industry accounts for 90 percent of all Genie product domestic sales and 80 percent of sales outside of the United States. Genie produces several types of construction lift equipment ranging from boom lifts, aerial work platforms, equipment handlers, scissor lifts, material lifts. AWP™ Super Series DPL™ Super Series IWP™ Super Series Articulating booms Telescopic booms Trailer-mounted booms Genie Lift™ Super Hoist™ Load Lifter™ Superlifts Super Tower™ Electric and engine-powered scissor lifts Rough terrain scissor lifts Compact telehandlers High reach telehandlers Runabout QuickStock Official website