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Sodium chloride
Sodium chloride, also known as salt, common salt, table salt or halite, is an ionic compound with the formula NaCl, representing equal proportions of sodium and chlorine. Sodium chloride is the salt most responsible for the salinity of the ocean and of theextracellular fluid of many multicellular organisms. In the form of edible or table salt it is commonly used as a condiment and food preservative. Large quantities of sodium chloride are used in many industrial processes, and it is a major source of sodium and chlorine compounds used as feedstocks for further chemical syntheses. A second major consumer of sodium chloride is deicing of roadways in sub-freezing weather.
Carbon
All carbon allotropes are solids under normal conditions, with graphite being the mostthermodynamically stable form. They are chemically resistant and require high temperature to react even with oxygen. The most common oxidation state of carbon ininorganic compounds is +4, while +2 is found in carbon monoxide and other transition metal carbonyl complexes. The largest sources of inorganic carbon are limestones,dolomites and carbon dioxide, but significant quantities occur in organic deposits ofcoal, peat, oil and methane clathrates. Carbon forms a vast number of compounds, more than any other element, with almost ten million compounds described to date,[14]which in turn are a tiny fraction of such compounds that are theoretically possible under standard conditions.
Carbon
Carbon (from Latin: carbo "coal") is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic andtetravalent — making four electrons available to form covalent chemical bonds. There are three naturally occurring isotopes, with 12C and 13C being stable, while 14C isradioactive, decaying with a half-life of about 5,730 years.[11] Carbon is one of the few elements known since antiquity
pottasium
The earliest known complete purification process for potassium nitrate was outlined in 1270 by the chemist and engineer Hasan al-Rammah of Syria in his book al-Furusiyya wa al-Manasib al-Harbiyya (The Book of Military Horsemanship and Ingenious War Devices). In this book, al-Rammah describes first the purification of barud (crude saltpetre mineral) by boiling it with minimal water and using only the hot solution, then the use of potassium carbonate (in the form of wood ashes) to remove calcium and magnesium by precipitation of their carbonates from this solution, leaving a solution of purified potassium nitrate, which could then be dried.[5] This was used for the manufacture of gunpowder and explosive devices. The terminology used by al-Rammah indicated a Chinese origin for the gunpowder weapons about which he wrote.[6] While potassium nitrate was called "Chinese snow" by Arabs, it was called "Chinese salt" by the Iranians/Persians
isotope of calcium
As with the isotopes of other elements, a variety of processes fractionate, or alter the relative abundance of, calcium isotopes.[8] The best studied of these processes is the mass-dependent fractionation of calcium isotopes that accompanies the precipitation of calcium minerals, such as calcite, aragonite and apatite, from solution. Isotopically light calcium is preferentially incorporated into minerals, leaving the solution from which the mineral precipitated enriched in isotopically heavy calcium. At room temperature the magnitude of this fractionation is roughly 0.25‰ (0.025%) per atomic mass unit (AMU). Mass-dependent differences in calcium isotope composition conventionally are expressed the ratio of two isotopes (usually 44Ca/40Ca) in a sample compared to the same ratio in a standard reference material. 44Ca/40Ca varies by about 1% among common earth materials.[9]
Calcium isotope fractionation during mineral formation has led to several applications of calcium isotopes. In particular, the 1997 observation by Skulan and DePaolo[10] that calcium minerals are isotopically lighter than the solutions from which the minerals precipitate is the basis of analogous applications in medicine and in paleooceanography. In animals with skeletons mineralized with calcium the calcium isotopic composition of soft tissues reflects the relative rate of formation and dissolution of skeletal mineral. In humans changes in the calcium isotopic composition of urine have been shown to be related to changes in bone mineral balance. When the rate of bone formation exceeds the rate of bone resorption, soft tissue 44Ca/40Ca rises. Soft tissue 44Ca/40Ca falls when bone resorption exceeds bone formation. Because of this relationship, calcium isotopic measurements of urine or blood may be useful in the early detection of metabolic bone diseases like osteoporosis.[11]
A similar system exists in the ocean, where seawater 44Ca/40Ca tends to rise when the rate of removal of Ca2+ from seawater by mineral precipitation exceeds the input of new calcium into the ocean, and fall when calcium input exceeds mineral precipitation. It follows that rising 44Ca/40Ca corresponds to falling seawater Ca2+ concentration, and falling 44Ca/40Ca corresponds to rising seawater Ca2+ concentration. In 1997 Skulan and DePaolo presented the first evidence of change in seawater 44Ca/40Ca over geologic time, along with a theoretical explanation of these changes. More recent papers have confirmed this observation, demonstrating that seawater Ca2+ concentration is not constant, and that the ocean probably never is in “steady state” with respect to its calcium input and output.[12][13] This has important climatological implications, as the marine calcium cycle is closely tied to thecarbon cycle
Calcium
Calcium has five stable isotopes (40Ca, 42Ca, 43Ca, 44Ca and 46Ca), plus one more isotope (48Ca) that has such a long half-life that for all practical purposes it can also be considered stable. The 20% range in relative mass among naturally occurring calcium isotopes is greater than for any other element except hydrogen and helium. Calcium also has a cosmogenic isotope, radioactive 41Ca, which has a half-life of 103,000 years. Unlike cosmogenic isotopes that are produced in the atmosphere, 41Ca is produced by neutron activation of 40Ca. Most of its production is in the upper metre or so of the soil column, where the cosmogenic neutron flux is still sufficiently strong. 41Ca has received much attention in stellar studies because it decays to 41K, a critical indicator of solar-system anomalies.
Calcium
Calcium is the chemical element with symbol Ca and atomic number 20. Calcium is a soft ay alkaline earth metal, and is the fifth-most-abundant element by mass in theEarth's crust. Calcium is also the fifth-most-abundant dissolved ion in seawater by bothmolarity and mass, after sodium, chloride, magnesium, and sulfate.[2]
Calcium is essential for living organisms, in particular in cell physiology, where movement of the calcium ion Ca2+ into and out of the cytoplasm functions as a signal for many cellular processes. As a major material used in mineralization of bone, teeth andshells, calcium is the most abundant metal by mass in many animals.
wikipedia
Wikipedia (
i/?w?k??pi?di?/ or i/?w?ki?pi?di?/ wik-i-pee-dee-?) is a free-access, free content Internet encyclopedia, supported and hosted by the non-profit Wikimedia Foundation. Almost anyone who can access the site[5] can edit almost any of its articles. Wikipedia is the sixth most popular website[4] and constitutes the Internet's largest and most popular general reference work.[6][7][8] As of 2014, it has 18 billion page views and nearly 500 million unique visitors each month.[9]
Jimmy Wales and Larry Sanger launched Wikipedia on January 15, 2001. Sanger[10]coined its name,[11] a portmanteau of wiki (from the Hawaiian word for "quick")[12] andencyclopedia. Although Wikipedia's content was initially only in English, it quickly became multilingual, through the launch of versions in different languages. All versions of Wikipedia are similar, but important differences exist in content and in editing practices. The English Wikipedia is now one of more than 200 Wikipedias, but remains the largest one, with over 4.5 million articles.
euro
The euro is the second largest reserve currency as well as the second most traded currency in the world after the United States dollar.[7][8][9] As of November 2013, with more than €951 billion in circulation, the euro has the highest combined value of banknotes and coins in circulation in the world, having surpassed the U.S. dollar.[note 14]Based on International Monetary Fund estimates of 2008 GDP and purchasing power parity among the various currencies, the eurozone is the second largest economy in the world.[10]
The name euro was officially adopted on 16 December 1995.[11] The euro was introduced to world financial markets as an accounting currency on 1 January 1999, replacing the former European Currency Unit (ECU) at a ratio of 1:1 (US$1.1743). Physical euro coins and banknotes entered into circulation on 1 January 2002, making it the day-to-day operating currency of its original members.[12] While the euro dropped subsequently to US$0.8252 within two years (26 October 2000), it has traded above the U.S. dollar since the end of 2002, peaking at US$1.6038 on 18 July 2008.[13] Since late 2009, the euro has been immersed in the European sovereign-debt crisis which has led to the creation of the European Financial Stability Facility as well as other reforms aimed at stabilising the currency. In July 2012, the euro fell below US$1.21 for the first time in two years, following concerns raised over Greek debt and Spain's troubled banking sector.[14] As of July 2014, the euro–dollar exchange rate stands at ~ US$1.35
euro
The euro (sign: €; code: EUR) is the currency used by the Institutions of the European Union and is the official currency of the eurozone, which consists of 18 of the 28 member states of the European Union: Austria, Belgium, Cyprus, Estonia, Finland, France,Germany, Greece, Ireland, Italy, Latvia, Luxembourg, Malta, the Netherlands, Portugal,Slovakia, Slovenia, and Spain.[3][4] Lithuania is adopting the euro as its official currency in place of the lithuanian litas on the 1st of January 2015
germany
Germany has the world's fourth-largest economy by nominal GDP and the fifth-largest by purchasing power parity. As a global leader in several industrial and technological sectors, it is both the world's third-largest exporter and third-largest importer of goods. It is a developed country with a very high standard of living, featuring comprehensive social security that includes the world's oldest universal health care system. Known for its rich cultural and political history, Germany has been the home of many influential philosophers, artists, musicians, scientists, and inventors. Germany was a founding member of the European Community in 1957, which became the EU in 1993. It is part of the Schengen Area, and has been a member of the eurozone since 1999. Germany is a great power, and a member of the United Nations, NATO, the G8, the G20, the OECD and the Council of Europe.
germany
Germany (i/?d??rm?ni/; German: Deutschland), officially the Federal Republic of Germany (German: Bundesrepublik Deutschland, pronounced [?b?nd?s?epu?bli?k ?d??t?lant] (
)),[11] is a federal parliamentary republic in western-central Europeconsisting of 16 constituent states, which retain limited sovereignty. Its capital cityand largest city is Berlin. Germany covers an area of 357,021 square kilometres (137,847 sq mi) and has a largely temperate seasonal climate. With 80.6 million inhabitants, it is the most populous member state in the European Union. Germany is a major economic and political power of the European continent and a historic leader in many cultural, theoretical and technical fields.